Two teenagers, both in need of computer access for schoolwork. Got a hand-me down MacBook with no hard drive. Had a 250GB drive that I had swapped out of my current MacBook when I upgraded it to 500GB. The problem - no bracket to hold the drive. Fortunately, iFixit had the hard drive bracket that I needed.
Having swapped out drives before, the installation was a piece of cake once I had the part I needed. The bracket came with the screws needed to attach it to the drive. Took me about 5 minutes to secure the bracket to the drive and install it.
If you are replacing a MacBook drive for the first time, Apple has a step by step guide called "Hard Drive Replacement Instructions" (073-1045). Very useful.