Heat the wire with a torch and when red hot melt your way through.
No way of risking damage trying to predrill a hole.
I'm going to be replacing my window weatherstrips in 2 days according to tracking.
Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.