That is a tough one. This might or might not work. Taps are hard steel. A very pointed hard punch might be able to bust it up enough to get it out. Most likely it was broke of after getting hung up on a chip, as most do it yourselfers' don't back out the tap every 1/4 turn or so. If not possible to remove, you might have to have the action re-tapped by moving all holes forward or back 1 a 1/4 " or so
