DRILLOUT LOCK JUST BENEATH WHERE THE KEY FITS WITH 8MM HSS DRILL BIT YOU SHOULD HIT 5 PINS OR TUMBLERS ONCE YOU HAVE TAP THE LOCK BARREL UNTIL TUMBLERS DROP OUT THEN INSERT ANY KEY OR A THIN SCREWDRIVER THEN TURN TO OPEN THE DOOR LOCK AS YOU WOULD WITH THE NORMAL KEY.ONCE THE DOOR IS OPEN REMOVE THE BARREL SCREW THEN SLIDE OUT THE BARREL.
DAVE. UPVC SERVICE ENGINEER, February 2009