Deadbolts are designed to be more secure than a regular lock and either operate with a key or simply at the turn of a knob on the inside of the door. If the deadbolt is old, it may fail and get stuck in either the locked or unlocked position. The remedy for a stuck deadbolt is to remove it completely from the door and replace it with a new deadbolt that functions properly.
Look at the deadbolt from the inside of the door and locate the two screws that hold it in place. Remove the screws. In some cases, you may need to pry off a circular cover with a screwdriver to access the screws.
Grasp the faceplate of the deadbolt and pull it away from the door. If needed, insert the screwdriver under the faceplate to facilitate removal.
Open the door slightly, or walk to the other side if it is stuck in the closed position. Grasp the outer deadbolt cover and pull it off. The outer cover does not contain screws or any other attachment method.
Walk back to the inside of the door and look into the hole left after you removed the deadbolt. Locate a small circle of plastic or metal in the centre and insert a screwdriver through. Push the circle toward the door with firm force to pull the deadbolt assembly out of the door frame. This step is only required if your deadbolt is stuck in the locked position.
Look at the side edge of the door, and locate the two screws on the rectangular deadbolt plate. Remove the screws with a screwdriver, then pull out the deadbolt from the door.