oldman is right.. two screws on the inside of the lock and the lock will open. you may find the cam stripped or just bound up because of lack of lubrication. In any event it can be turned to retract the bolt. Take the two screws on the door face (one above the bolt and one below) and remove the bolt itself. Either lube up everything and get it working with graphite or toss and get a new lock. It can be easily keyed to your other locks at Lowes or HD for about 5 bucks. I do them myself since I have a lock pin set.