Place the key in the lock and gently pull it towards you as you turn it to the left (10 o’clock) or right (2 o’clock) positions to align the cam. When the cam is aligned, the lock should slide out towards you. With the door open, turn the key so the bolt is in the locked position and remove the key. Then remove the screws holding the faceplate in position. Remove the internal door handle and the spindle bar connecting the two handles. Retain this for refitting later. If the new lock body or faceplate is larger than the old, use a hammer and wood chisel to enlarge the mortice (hole) so the new lock fits properly in place. Once the lock body is in place, screw the faceplate into position. Then, replace the spindle bar and handle. Check that the new key turns smoothly in the lock. Remove the existing strike plate from the door frame, then hold the new one in position to test its fit. If need be, mark where adjustments need to be made to the recess, before using a hammer and wood chisel to remove the excess wood. If the overall length of your replacement lock is longer than the old one, use a hacksaw to shorten the tail bar so the two locks are the same length. Screw the lock body ...