Just locate the dark green and grey on the RHS of the selector assembly. They run from the dip switches on the LHS, around the back and into a white pin block. There is plenty of slack in the wires, so cut them at equal points at the most assessible point, swap them and join them with either crimps or solder and heatshrink.
I also found one of my bulbs was gone, replaced it, took that silly blue cover off the bulbs, still not that bright and I dont think it would ever light up the + and - unless you use some serious wattage, rather strange design from Mr nissan san.