Once the battery has been removed, we will remove the 4 screws in the battery compartment and then the 4 screws around the back of the case. These 8 screws use the Y0 bit. Each of these screws are 5.5 mm.

The four screws on the outside are extremely deep into the casing, and the holes are pretty small. You will need to use a 4 mm driver bit extension to reach these screws.