Remove the following 4 screws from the back of the computer:

Two 11 mm Phillips #00, with Shank (2.2mm dia. x 2 mm len.) (Head: 3.2 mm. dia. x .5mm thick)

Two 7.25 mm Phillips #00, with Shank (2mm dia. x 3.75 mm len.) (Head: 3.2 mm. dia. x .5mm thick)

During reassembly, the two longer screws go on the inside, and the two shorter screws go on the outside.