Remove the six Phillips-head screws under the rubber feet around the bottom of the case.

Flip the case right-side up, and lift up the top to remove the bottom plate.

There are four main components underneath:

The main PCB, which holds the main buttons, surface-mounted chips, and connections to the other three components.

the joystick, connected to the main PCB by eight wires soldered to each part of the stick's microswitches.

the turbo daughterboard, a small PCB with a switch and an LED, wired to the main PCB, intended to enable turbo functionality on the main buttons.

the menu button daughterboard, a long PCB with three small push buttons, with a simple ground connection back to the main PCB.