!!! VERY IMPORTANT !!!
The computer you are going to install Snow Leopard on MUST be setup with the GUID partitioning scheme. The external HDD can be anything as this is just booting for the install, but the actual drive in which you are installing Snow Leopard onto must be setup with the GUID partitioning scheme.
!! Instructions External HDD Method !!
Tested and Works
* On your external USB or Firewire HDD, create a 10GB Mac OS X Extended partition, format this partition and leave it blank. You will need this later on.
* Mount the .DMG file
* Using Disk Utility, Select the RESTORE Tab
* Right Click on the "Mac OS X Install DVD" and select it as the SOURCE
* Right Click on your USB/Firewire 10GB Partition and select it as DESTINAION
* Check off "Erase Destination"
* Click Restore
* Wait for Restore to complete
* Once restore is complete, you will notice that your 10GB Partition name is called "Mac OS X Install DVD"
* Unmount the Disk Image
* LEAVE THE USB/FIREWIRE DRIVE CONNECTED
* Restart your Mac and hold the Option Key to get the startup disk menu
* Select the External HDD, Labelled "Mac OS X Install DVD"
* Booting from the External HDD works and it's fast!! Anytime you want to install Snow Leopard on any Intel Mac Computer, all you need to do is bring your External Drive, connect it, reboot and install.
!! Instructions DVD Method !!
Untested. Not sure if this works as I use the External HDD Method
* Mount the .DMG file using Disk Utility
* Using Disk Utility, create a new dual layer (8.5GB) sparse image called snowleopard (actual filename will be snowleopard.sparseimage)
* Mount this new sparse image file
* Restore the SnowLeopard Install DVD you downloaded from RapidShare to the newly created mounted snowleopard.sparseimage (not the image file.)
* Open the mounted snowleopard.sparseimage with Finder, and delete the XCodeTools directory.
* Unmount the mounted snowleopard.sparseimage.
* Using the Disk Utility, create a new single layer (4.4GB) spare image called snowleopardboot (actual filename will be snowleopardboot.sparseimage) and mount it.
* Restore the snowleopard.sparseimage image file to the mounted snowleopardboot.sparseimage (not the image file.)
* Unmount the mounted snowleopardboot.sparseimage.
* Burn the snowleopardboot.sparseimage to your single layer DVD media.
* Booting from this DVD works, but takes a very long time.
I get CPU Panic!
Intel Quad Q9300