The guide is misleading. You shouldn't merge files but replace them. Then, you should have the correct config.plist file and the right kexts in EFI/Clover/kexts/10.10.
You also made a confusion between the EFI partition that the Clover Install pkg should have created on your USB pen and the EFI folder which is meant to be in the EFI partition.
Therefore, you don't need to create/rename folders or files which is why boot fails. So my advice is to totally wipe out any files in the EFI Partition (even the hidden ones) and start from the beginning when it comes to install Clover on your USB pen (no need to entirely recreate the USB pen).
BTW, Optiplex 760 series doesn't use UEFI Bios, just legacy one so don't worry about that, just make sure AHCI is enabled. That's it !
I'll post my experience and ways how I installed Mountain Lion 10.8.5. If you don't have this image, you can find them on the known torrent places. (Mine was a torrent what didn't work directly with MyHack, I had to mount the .dmg first and could select the installer inside this .dmg to get it working with MyHack)
I used several sources for this guide. Mainly the files given by DoiX. And for the guide layout I used pepto guide for his Mavericks on a Dell Latitude E6320
1. My specifications:
Dell XPS 15 L502x
SSD harddisk location (Windows 7)
HDD caddy location (Data + OSX)
Dell XPS L502x - L702x and 15z will probably also work
A working Mac OS X installation - original or hackintosh. You can use iAtkos L1 to make your L502x a hackintosh on a simple way if you don't have access to one
A copy of Mountain Lion - I guess all version will work, I used 10.8.5
MyHack - you can use the latest one from their site or the one in the package
A USB flash drive of 8GB (or larger)
My zip file - This files contains all the files I used
3. Preparing your SSD or HDD for install on a MBR-partitioned drive:
If you intent to install Mountain Lion on the same Hard disk as your windows follow the steps below. I also followed these steps to install Mountain Lion on my second harddrive together with my NTFS data partition.
For a clean full install on a new formatted hard disk go to Chapter 5.
If you’re in Windows 7, you can easily make a new partition on an SSD or HDD via the Disk Management program.
Start>Run (or Windows key on your keyboard plus R). diskmgmt.msc (press enter after typing that) Find your drive, right-click on it, and go to Shrink Volume. Wait for it to calculate the amount of space you can make your partition, and enter in your amount. Let it make your partition. It will show up as unallocated space. Format the new unallocated space as exFAT and give it a label (I called it OSX). You can probably also format it as NTFS or FAT32 because you are going to format it anyway.
4. Create OS X 10.8.# Install Disk (USB)
Start OSX Mavericks, (Mountain) Lion or Snow Leopard to prepare your USB Flash drive
Make sure to backup the files that are already on your USB flash drive.
Extract the zip file L502x_ML10.8.zip to your Mac OS X desktop If you don't have already installed myHack then install MyHack from the Utility folder and follow the steps. Plug your USB Drive into your computer, and start myHack. Enter your Mac OS X password when the app begins, and setup process will begin. When myHack prompts you, select “Create OS X Installer” and Create OS X 10.8 Install Disk”. Select your USB Drive as the installation destination. myHack will ask you for the location of your copy of OS X 10.8 Mountain Lion. Use 'Browse Manually' and locate and select you 10.8.# image. myHack will begin to set up your installer USB Drive. Click “Ok” when myHack asks to erase your USB Drive, so that it can begin the setup process. From here, the setup process is pretty automatic. myHack will erase your USB Drive, copy the contents of the Mavericks installer app onto it, and then modify those contents to be bootable on a PC. Near the end of the process, myHack will ask you whether you want to apply the MBR patch to the USB Drive. Click “Yes” if you plan on installing Mac OS X on a hard drive where windows is already installed or “No” if you wanna installing Mac OS X on the entire hard drive. This entire process should take about 10 – 15 minute, though it may take up an hour if your USB Drive is slow.
5. Adding the Extra folder to your USB drive:
Now, we need to put the Extra directory for the L502x on the USB Drive so that it will properly bootup on your PC.
Start myHack, Enter your Mac OS X password when the app begins. When myHack prompts you, select “Install Extra”. myHack will ask you “Select target volume to run myHack on…”, choose your “myHack OS X 10.8(.#) Install Disk” and choose “Ok”. myHack will prompt you “Do you want to use the generic Extra that comes with myHack or specify tour own?” choose “Use My Own” and press “Ok”. Browse to your early extracted “L502x_ML10.8 – Extra” folder on your desktop and choose “Open”. myHack will copy the Extra folder to your “myHack OS X 10.8 Install Disk”. When finished you will see the message "myHack Finished" press ok and Quit to close myHack.
6. Installing OSX Mountain Lion from your USB drive:
Boot from your USB drive. If everything goes right you can boot without flags or use -v if you want to see what happens. If it doesn't boot, you can try one or more of these flags:
-f -x GraphicsEnabler=No busratio=20 (depends on your type of CPU) cpus=1
Once you get into the installer (assuming your computer didn’t freeze, restart itself, or get a kernel panic), choose your partition or Hard Disk to install OSX Mountain Lion to.
NOTE : when you install it on a partition skip step 5 - 10 see Chapter 4. (If you install Mountain Lion on the entire Hard disk follow the steps below ) In the installer open up Disk Utility. Click on your Hard Drive in the left sidebar. Click on the Erase tab in the middle. Choose “Mac OS X Extended (Journaled)” as the format, and give your drive a label (like “OSX”). Click on the Erase… button. Done close Disk Utility and go further with the installation process. Choose your HDD or Partition to install Mountain Lion to. The installation process will take about 23 minutes, depending on the speed of both your USB drive and your SSD or HDD. myHack will then ask to remove a couple of unnecessary kext files—click “Yes” for all of them. myHack will also prompt you to install an “Extra” folder. Choose the second option, which lets you install your “Extra” folder. Select the “Extra” folder from your USB Drive, and wait for the installer to finish. When finished let the system reboot and use your USB again to boot into the Mountain Lion installation.
7. Booting OSX Mountain Lion:
In my case, OSX doesn't boot without help, so you need to boot from USB again. Choose the partition you installed Mountain Lion to. You can start it without flags or use -v to see what happens. You’ll eventually get to the setup screens for OSX Mountain Lion. Go through that process to setup OSX Mountain Lion. Choose by "How Do You Connect" for "My Computer Does Not Connect to the Internet". The installation process will take about 3 minutes.
8. Post installation Mountain Lion:
Open the Lx02XMountainLion_V1.4.zip from the L502x_ML10.8.zip and run the installer. And choose the following option to install. (Some are probably not needed, but I didn't know for sure)
Sensor Modules Keyboard & Trackpad Disk
MacBookPro 8.2 (use this if you have an i7)
FullHD Screen (of course take the other one if you don't have a FHD screen)
After finishing this installation you will probably get the an error. Just ignore this. Open MultBeas from the utility folder and choose the following options:
Drivers & Bootloaders
PS/2 Keyboard/Mice and Trackpad USB 3.0 Universal
Realtek - Lnx2Mac's
Again you will probably get an error after finishing your installation. Again ignore this. Drag all the Kext files from the kext folder over "Kext utility.app" (contained in folder “Utility") and release the mouse. Type your root password and the Kext files will be installed on your Hard disk. Open Disk Utility and repair the permissions of the Mountain Lion partition.
Now you can reboot the system and use the USB installer to boot the Mountain Lion installation. If things went right, you can still boot without flags.
I don't know yet if there are problems with this installation using 10.8.5 because I made this guide directly after it. It seems good for so far.
The only problem I got is how to make this system bootable. To be clear, I got a SSD on my original harddisk location. And places the old HDD in the caddy. And the HDD has 2 partitions:
What do I have to do to make OSX bootable? I want to keep Windows 7 as only OS on my SSD and in the original HDD location. So how can I make my laptop to boot my SSD (my Bios can only boot into that drive) but give me the option to boot or Windows 7 of my first disk (SSD) or OSX from my second disk (HDD)