I bought spare Ford cap for our 75 F-150. The plan is to swap the back
lift gate. HOWEVER…the latch on one side is stuck closed. Locked, no key.
I unhooked the rod and moved it with a channel-lock wrench. The latch
assy. will not move. Cutting the parts by the latch with a saw-zall will
destroy the fiberglass. Am I SOL? Perhaps a big bolt cutter?

Did I write BOLT CUTTER? Today I used a bolt cutter to destroy one of the aluminum
latches held in place with big phillips screws. A chisel and hammer finished the job.
The latch parts on the edge of the lift gate are rusty.
I removed the bolts along the hinge line and was forced to destroy the slider on each side.
The spare/good lift gate is now removed. Next step is to repair the lock assy and the
rusty latches on each side.

QUESTION: What is the best way to remove those stubborn phillips head screws?
Drilling is last resort.