Yes it was a PITA. I had to drill though a rib channel that was just below the window. Then pulled a wire through the opening. My outdoor scare light worked but the over the door "porch" light didn't, no power going in to the switch. Put a long extension on the drill like about 8" and had to pull out the switch and AC outlet box (cut all electric power to the trailer during this).
Then was able to get the drill in sideways to drill through the alum. NOTE: I did also puncture the outside skin in this process with a BB size hole, so be careful. Think used about a 1/3" paddle bit. After drilling, used a coathanger pulled the wire through to the other side and replaced the dead wire going into the switch. Voila lights on now. There were a lot of strange wires going to/from the switch and they were different colors at the light so I haven't a clue what was up on the original wiring. To test the concept you can use a wire from the hot side of the scare light and run it outside the panel over to the switch on the porch light. If it works then proceed with drilling pulling. I used a meter to test the power on both switches (DC 12V). This told me what the power was supposed to be going into the switch and that there was 12V
on the scare light but not on the porch light.