I thought I would just share my experience. It's the first surgery I've ever performed on a mac aside from RAM installation, so it was kind of exciting for me. I have a ton of music, movies, and TV shows, so my 80 GBHD wasn't cutting it. I had already transferred much of my material onto an external so I could fit my new TV episodes on the computer. It finally got to the point where i couldn't even save an excel document and I was running extremely slow, so I went to Amazon and bought at Western Digital 320 GBHD for $70 as a replacement. When it arrived yesterday, I went to my local Ace Hardware store to buy the Torx T6 driver and jewelry phillips head that I needed to do the job. I printed these instructions I found on a google search. I was surprised at how easy it really was. As long as you stay organized and keep track of the screws (I labeled them by step in separate containers so I wouldn't have any problems putting it back together) you're fine. Now, my computer feels like it's brand new. It's got all kinds of pep. Copying files and transfers feel a lot more peppy and the times seem to be reduced. All of my applications launch quicker as well. I'm surprised at how much a new Hard Drive really helps the response time. One question though. When I booted my computer to install OS X, I used disk utility to format the drive. For some reason, the computer only recognized it as a 297 GBHD, before I had installed OS X. Anyone have any idea why that is? Aside from that, I'm very happy. It was a fun project, and it's really easy to do.