Remove the screws from the controller using a Phillips screwdriver. Seprate the back cover from the front and carefully remove the PCB from the enclosure.
Dump all of the buttons and elastomers onto your work surface or palm of your hand. Admire and store in a baggy for later use.
Secure the SNES PCB to a panavise Jr. Heat up your soldering iron and reflow the solder poins on the main cable. Use a pair of tweezers to gently remove each wire from the PCB. Toss cable over shoulder - won't be needing it.
Ensure SNES PCB is very secure to panavise Jr. Reference diagram to follow where to split the sections. Move to a well ventilated area and put on some safety glasses.
Use a power tool like a Dremel to cut the PCB into three sections. Handle panavise jr. in place before sawing. Slowly saw through the PCB until you've reach about 1mm - break away sections with hand.
Remove the L shoulder PCB from D-Pad by reflowing solder from the wire using a soldering iron. Remove the bit of cable soldered to the L shoulder PCB.
In this project, we won't be needing the D-Pad PCB because we're using the analog joystick - Disgard that PCB or store it away for another project.
Secure PCBs to a Panavise jr. Use a sharpie marker or etch a mark in the very center of the buttons PCBs. Use a rotary power tool like a Dremel to create a hole in the center of the A, B, X, Y button PCB. Use a drill bit that is approximately 2mm in diameter.
Use an x-acto or filing tool to expose copper traces on the PCB sections. Reference the images for recommended etching spots. Lightly scratch the surface of the silk screen until the copper traces are exposed.
The PCB section with A, B, X and Y have very small traces - be very careful not to bridge these connections! Try offsetting each spot in different levels to keep wiring seprate from each other.
The L and R shoulder PCB don't need etched traces since they both have pin outs for wiring positive and negative connections.