Place the front acrylic panel face down such that the small notch is to the bottom and the D-pad is on the right side. Place the screws pointing up through the holes.
Place a button cap in each of the holes face down.
On each of the four screws place one of the longer (6mm) spacers on top of the acrylic
Place the PCB face down with battery holder
After the PCB is placed, add one of the shorter spacers on each screw protruding through the stack.
Make sure that it is oriented the right way so that the notch for the battery wires is on the left hand side where the wires come out.