Things You'll Need
Instructions
Turn the NES controller upside-down, and remove the six screws using a Philips screwdriver. Remove the cover case, leaving only the controller board.
Snip the five colored cables where they extend from the black wire cover. Discard the cord. Strip the colored wires, leaving one or two millimeters of each wire exposed, enough to solder with.
Add solder to each end on the five wires. Add solder to the bottom middle two contacts on the top of the RetroKit board. Flip it over and add solder to the middle three contacts on this side.
Hold the RetroKit board so the contacts that connect to the NES controller wires are on the bottom and the USB wires extend from the left. Solder the brown NES wire to the middle left contact and the white NES wire to the middle right contact.
Flip the RetroKit over horizontally. Solder the orange NES wire to the middle left contact on the RetroKit, the red NES wire to the middle contact and the yellow NES wire to the middle right contact.
Put the NES controller board back into the casing, and replace the screws to close the controller. Plug the controller into your computer. It will automatically detect the controller, making it ready to use.