How to remove a Yale commercial door knob will depend on the type of door knob used. In most cases, doorknobs can be removed by following basic steps of removing the screws to then remove the rest of the door knob. Once the screws are removed, pull the door lock face off the door. Simply grab the lock face on the outside of the door by the door handle and pull straight toward you to remove. If this is a mortise lock, then look at it from the side, and use a screwdriver or drill to remove the screws on the side of the mortise lock. Pull off the face plate, and any other hardware. Pull the mortise lock out of the side of the door.