IT SHOULD POP RIGHT OFF THE ONLY THING LEFT HOLDING IT ON IS RED LOCKTITE. PLASTIC HAMMER. IF YOU LIVE CLOSE TO GLOCK INC. THEY WILL FIX IT FOR FREE OR YOU CAN HAVE THEM SENT YOU A SCREW UNLESS IT BROKE OFF IN THE SIGHT, IF SO SEND THEM THIS PICTURE AND THEY MIGHT JUST SEND YOU THE SIGHT AND SCREW.