Yep, finally built up the courage to replace the UJ-85-JC superdrive in my 2ghz 20" Aluminum iMac. Taking it apart was remarkably easy (following the excellent advice from http://www.amfiteatar.org/content/view/155/57/lang,en ) and replacing the superdrive was also not a huge problem. The most troublesome part of the task was ensuring the drive eject slot matched the casing exactly - only really troublesome as you have to keep taking it apart until you get it lined up! Replacement superdrive was an Optiarc DVD RW AD-7633A - System Profiler finds it and it "just works" (not bad for £42.52 including £4-50 shipping!!) Anyway - the point of this thread is that is isn't as hard a job as it looks - I even managed to do it without disconnecting all the screen leads mentioned - most were long enough to prop the screen at the side of the case. I can put the external DVD drive away again!!