Step 6: Modify the Enclosure
In order for the circuit to contact the tape on the guitar's neck, we're going to add copper tape contacts to the outside of the box that will line up with the tracks on the guitar.
This part is hard to describe, but look at the picture and it will make sense...
First, you need to position the enclosure on the neck and mark where would be a good spot for those contacts. Then, cut 5 strips of copper tape wide enough to serve as reliable contacts and long enough to reach around the edges of the box and reach inside. Finally, cut a thin piece of foam that is wide enough to cross all 5 contacts. These strips are going to be laid parallel to each other along the outside of the box and over the foam so that when the box is pressed to the guitar head, the foam presses the tape against the traces on the neck. Apply the tape so that it also goes into the inside of the box.
Now that the contacts are installed, cut 5 small strips of wire and solder these to the section of the contacts that reach inside the box. Then solder the other ends to the circuit board.
Finally, insert the circuit board into the enclosure, mark out holes for the buttons and outgoing wires and cut those out.