Easy enough, I've been around for a while, however I'm not up on forum policies for external links and such...
1. download Lion from the market.
2. download chimera 1.4.1 (google) or whatever build of chameleon you prefer
3. download xmove 1.0 (google)
4. resize your leopard partition to leave 11.5gig of free space at the end
5. create a new partition in the empty space, name it install
6. Run xmove, and make sure you choose the partition 'install' as your destination!! (if you install it to your snow leopard partition you'll break your setup)
7. Once that is complete make sure you have either updated your chameleon, or you have run chimera.
8. reboot, at the boot screen select install as your boot device, and install!
9. once in lion copy any of the files you like from the attached archive (most of which are based from this thread, and some are not), to get sound working use the archive provided by the thread starter here. I think you'll need the network kext provided there as well, but I'm running on wireless so I never bothered.
10. Open terminal and paste:sudo perl -pi -e 's|\x8b\x45\xc8\x39\x45\xcc\x74\x0b|\x8b\x45\xc8\x39\x45\xcc\xeb\x0b|; s|\x8b\x45\xb4\x39\x45\xb8\x74\x08|\x8b\x45\xb4\x39\x45\xb8\xeb\x08|' /System/Library/Extensions/AppleRTC.kext/Contents/MacOS/AppleRTCyou may wish to backup /System/Library/Extensions/AppleRTC.kext first.
**Make sure you've updated your bios to FF
*** All you fermi users NO MORE FREEZING!!!!!!! I gave up on lion with my 5750, so I put my GTS450 back in just to test the waters, and no freezes!! (this isn't exactly news at this point).
Make sure you run kext utility before reboot.
JPA has a much prettier, and well thought out guide here
My geekbench under SL was 8950
My geekbech under lion is 10970!! (I think nullcpupowermanagement was slowing me down under SL)
Updated to 10.7.1 this evening, sound was broken as usual, after reboot I put the attached kext back in s/l/e , ran kext util, and all was back to normal.