There is no electrical bypass. You've got 1 power wire, 1 ground. If either one is toast the PTT function is toast. I guess you could take 12v direct to PTT unit with ground, but then you're cutting wires that you not have to cut. There is an easier way....Frozen is a.k.a corroded. Take a pinpoint torch and heat the screw. Or if you really want to get nifty, heat cycle the screw by using automatic transmission fluid, or any other nonflammable lubricant. Squirt the lube on, torch the screw. Let cool. Unscrew. If it doesn't unscrew, keep repeating heat cycle until does. It's a small diameter screw so it will respond to heat quickly. Heat solves all corrosive lock-up issues.