I'm thinking MAYBE I'll just try operating this 2010 from an external drive, but I have NO CLUE how to do this. Here's what I want to do, and I need someone to tell me how practical, easy (cuz I'm seriously clueless here) and inexpensive this would be. I'm thinking for my needs at this time, this might just be the way to go, even though those new retina displays are calling my name... Anyway, to truly weigh my options, I just want to know how complicated this would be and how much of a pain on a daily basis to run the computer this way. I'm a turn on and go kinda gal, so if it's a pain, I'd rather just get a new iMac. Priority is backing up the photos/videos stored on this hard drive. Then, either use computer as-is till hard drive dies, OR update it as much as I can (currently running Yosemite) and then copy OS over so I can boot from an external drive (need to know exactly what this entails when booting it up), OR Try to change out the hard drive inside it, which scares the bejeezus out of me. Can someone explain this in the "for Dummies" version, since that seems to be the only way I can begin to understand? I've asked so many questions I'm confused as hell.