The knee bolster is removed and the light wiring harness is snaked through a hole in the firewall and out into the engine compartment. The six wires are grounded, snaked to the lights, attached to an inline fuse and then attached to the B-block in the under-hood fuse panel. The remaining harness is snaked to the bolster switch, two to the radio, and a final wire to the Body Control Module (BCM) in the passenger footwell. You can see the green light relay in the lower left hand corner of the image.