QUOTE (Ramm @ Jun 11 2007, 09:41 PM)

Firstly, and obviously, get the new .kext you need.
2) Go to System/Library/Extensions in Finder
3) Put the new .kext file in that folder. If you are replacing an old one with the same filename, move (not copy) the old one to the desktop, and put the new one in it's place
4) Go into Disk Utility (Applications -> Utilities -> Disk Utility). Select your OS X volume and click Repair Permissions.
5) Reboot.
Not forgetting that we need to remove Extensions.mkext and Extensions.kextcache in /System/Library