I've read ifixit.com's description of how to swap out a MBP hard drive but for those of you who have actually done it, how difficult is it? the only thing i've ever done to my computers is installing new RAM. I know I need the special screwdrivers but how tricky is it to disentangle all the cables that are attached? If you've already done it before, how long did it take you to swap out your drive (not including reinstalling OS and restoring all your data)? I have a Rev A MBP from 3 years ago. Thanks.