place in a vise, not real tight firm enough to hold it. Start to back them off with lineman pliers, finish by hand. If they're not in real bad shape you can just reuse them. Mix up a lil epoxy and set them back in place
snap off they will...been there..........once they get rusted inside the wood ,they become welded to the wood.....course on the other hand you can always drill a new hole against the old shaft for a new screw eye.