How's your soldering skills?
Things that make soldering easier are a good iron with a clean tip, wire strippers and push back cotton covered wire (not the thin stuff that comes with the kit)
You can lay out the potentiometers through a card template so they are spaced the same as the body holes and then solder all the wires between them, referring to the Pitbull wiring diagram for your kit. That way you don't have to reach into the body cavity with the iron, and you can solder most of the joints before you assemble the instrument