Remove the following 3 screws:

One 11 mm Phillips#00 in the middle of the lower case. (Head: 5mm dia. x .75mm thick)

Two 14.5 mm Phillips #00 (Head: 5mm dia. x .75mm thick)

If the screws stick in the case, you can use a magnetized screwdriver to draw them out.

The shorter of the three screws goes in the middle of the lower case.