Remove the following screw and standoffs (the standoffs progress from smallest to largest):

One flat-headed Phillips screw near the left side of the RAM slot.

The smallest standoff, near where the left hinge used to be.

The slightly larger standoff, near where the right hinge used to be.

The even larger standoff, near the right side of the RAM slot.

The largest standoff, above where the optical drive used to be.