You can extend the wires to the front of the bed curl and then down to the wiring harness or you can bring them down through the rear stake pocket to the taillight wires. Some trucks have a gap between the stake pocket and the curl, which allows the wires to be threaded down into the rear stake pocket and to the wiring at the rear cross sill. Depending on how tight your stake pocket or the bedside top curl fits to the bedside skin, you may need to drill a small hole to feed the wires from the bedside curl into the front face of the rear stake pockets. If there is no gap between the end of the rear sill and the stake pocket, you will need to drill a medium-sized hole in the rear cross sill to allow the wiring to pass through. Use grommets and sleeving to protect the wires from chaffing against the sheetmetal edges.