Replace rear window latch cable

Sht45

The rear window latch cable is broken. I replaced the lift gate latch cable easily enough but I can't replace the rear window cable without removing the latch from the gate. However the four screws are immovable & I'm afraid of ruining the heads. The screws are not rusted & look like new but they are really tightened down. Is there a way to replace the cable w/out removing the latch? If not how can I remove the latch w/o damaging the screws?