l have lost the key for my back door upvc door and it is unlocked so l need to replace the lock... l took the long screw out the side of the door and the cylinder was loose but l cannot get the cylinder out, l know it has to have a key to turn the safety bit in the middle of the barrel to get it out so have tryed to drill the lock but keep snapping my drill bits can someone give me advice on how l can get my barrel out to replace it as the local store have them in... Good job l have a yale lock on till l get this done....