Remove the three PH00 screws.

Pry out the metal cover over the buckle lock. Be gentle so as not to bend the metal.

The spring loaded buckle lock can then be removed. NOTE: Do not loose the spring when disassembling. Reassembly can be tricky because the spring needs to be compressed to get back in place.

The plastic cover over the holes in the middle of the rail can be removed. This is where SL, SR, and connect buttons would be on a normal Joy Con controller and also the lights indicating which controller number it is.