I am pretty sure that one of the tools listed as needed has changed from when I looked it up last week and placed the order, and is a mistake. Here is a screen shot of the first step to replacing the fan on my Mac unibody. Doesn’t a 3mm Phillips call for a #1 PH screwdriver? Is the mistake in the size of the screw or the screwdriver designation? And I am sure the last time I looked it did not say I needed to remove 13.5 mm Phillips screws. Maybe I can figure it out, but I once ruined a laptop by dropping a back screw from the screwdriver into the innards. I never found it - until it rattled around and ruined the computer! Should I guess? What does everyone think?