Hi hIPPYsHAKE,

Please note that I have not built this kit. But the wiring diagram does need changing!

The PURPLE wires (which are not shown on the diagram) are the ground wires and would be presoldered onto/joining all the pots and the ground to the jack socket. They may not be purple! So do not worry about these.

The Pickups may not have a metal wire sheath. If they have a black (ground) and coloured (or white) wire then solder the black wire on to the back of the pots like shown on the wiring diagram. The half-way along the wire in the diagram is misleading and represents the sheath and wire inside the sheath (and the sheath would be connected to the frame of the pickup).

I hope this helps.