Remove the six 6.2 mm screws using a Phillips #00 screwdriver

Remove the 2.3 mm screw located above the game cartridge slot with a Phillips #00 screwdriver.

With a plastic opening tool pry off the lower case starting at the bottom edge and working around the perimeter.

Two ribbon cables connect the case to the circuit board. Be careful to not pull the case too hard and rip the ribbon cables.