In this video, Ask This Old House general contractor Tom Silva shares some tricks of the trade for backing out stripped screws.
1. Try removing the stripped screw with the proper size manual screwdriver.
2. If the screw head is protruding from the surface, grip it with self-locking pliers and twist out the screw.
3. Use a cordless drill—set in reverse—and left-handed bit to drill a small hole into the head of the stripped screw.
4. With the drill still set in reverse, use a screw extractor to back out the screw.
5. If the screw head has snapped off, use a hollow-boring screw extractor to drill out the entire screw. Fill the resulting hole with a tapered wood plug.