Cannot remove door knob

I am trying to remove a Dexter keyed door lock set, but it has no visible screws showing anywhere The door is over 35 years old

This video shows how to replace a door knob; with or without screws, and both locking and

doorknob without screws How to Take Off a Door Knob With No Screws · Open the door · If the knob has a recessed setscrew, turn the setscrew counterclockwise with a

how often is the postcode lottery drawn Locate the hole on the doorknob shaft, insert a small flat-head screwdriver and press inward to release the doorknob It will now pull easily