Key broken off in trunk lock

I've heard of a couple different suggestions: try using a very small serrated blade, like a coping saw blade and slide it under the key and hook it and pull it out. Anything that you could slide beneath the key I suppose would work. Heard also of using a hairpin or a paper clip. Also one fellow said put a drop of superclue on the other portion of the broken key and inserting it back into the lock and connect to the broken piece. Good Luck