Quite simple really. If you have the 10.8.2 update on disk, use an app called Pacafist (google it). Mount the 10.8.2 combo.dmg, right click on the OSXUpdCombo10.8.2.pkg file and open with Pacafist. Pacafist is a pay app but will let you use it with a little wait. It will open a window showing the contents of the pkg file. expand the pkg folder, expand Contents of manual, expand contents of OSXUpd10.8.2.pkg. This will show you the folders containing all the files which may be used during an upgrade. Go to Sytem/Library/Extensions folder and drag GeForceGLDriver.bundle to your desktop. Use Kext Utility to install it (if you want it installed properly with repair of permissions and rebuild of kextcahe) or use Kext Beast (I personally don't recommend Kext Beast as a kext install tool.) If you have to use KextBeast, make sure to run disk utility afterwards to repair permissions and use Onyx to rebuild you kextcache. Those are the 2 main things Kext Beast does not seem to do / or do properly.
That simple really. It's even easier if you back up any kext which gets updated or replaced as part of a 'fix' before you make the changes. It just makes life that much easier to go back.
I could just upload it for you, but then you would not be learning anything new.
