Drilled the hole where the tail position light wires will go through the F810 bulkhead. - Tight access but I got it done. I then drilled a hole in the aft deck and horizontal stab end rib to allow the conduit to go up into the left horizontal stab for the elevator trim wires. I also tied fishing line to some cotton and blew it down the conduit so I can pull the nav light and elevator trim wires.
Conduit routed up through the aft deck. Note the hole in the end rib of the left HS.