Hi, The lower security pin ( long section that slots into recess on base of door frame) has become detached from the handle making the 3 point lock inoperable. How do I re-attach to the locking mechanism on the handle so when the handle is lifted up to set the securing pins into location both top & bottom ones engage ? The top one is ok at the moment when the handle is lowered to release it drops down into top of door frame but the lower one stays down jamming the door.