An old boatbuilder's trick for loosening wood screws.
Step 1: Supplies!
You will need:
A stuck wood screw - in this case a smallish, thinnish, bronze slotted flathead screw.
A length of steel rod matching the size of the screw head - I used a 20d nail.
A propane torch.
Vise-grips - 'cause your gonna make that nail HOT.
A screwdriver that fits the screw well.