Make sure you ground yourself to prevent static discharge. Everything else is straightforward. Use the proper size philips to get the cover off. Remember which holes have the longer screws. Some go in at an angle. You will need a #6 torx screwdriver to get the hard drive prongs off and on. I bought a set at Radio Shack. After I put in my new hard drive I re-installed Mac OS from the discs that came with it. It was new, so I had no data on the computer. SuperDuper is a clone program that works very well. If you have a bunch of data and you want to change the hard drive, you can clone your existing drive, remove it, and put the new drive in and re-image from the clone back to the new drive. Good luck.