I just completed this on my white macbook which I purchased in 2007. First, while in steps 19 and 20 they tell you to remove all four fan screws (two that hold the fan to it's lower housing, and two that hold the housing to the computer), they then only remove the fan without the housing. The entire housing should be removed in order to clean the heat sink behind the top of the fan. My replacement fan came as one unit anyway, so I replace the entire thing. Second, after many heating and cooling cycles, the black felt tape described in Step 20 was degraded and not able to be removed from the fan without ripping it. I replaced it with a couple layers of electrical tape (hopefully it holds up), but I would recommend getting the correct replacement tape before replacing the fan. Otherwise, if you're used to working on electronics and are relatively patient, it's actually pretty easy to do.