Genuine security knob locks CANNOT be disassembled, without damage, if its key cylinder is not rotated.
When installing these locks, DO NOT over tighten the lock screws. Best use finger tip torque.
Lever locks comply with the Americans Disabilties Act. These are required in public and employee access premises, such as schools, hospitals, business' etc.
Screw mortise cylinders all the way in, if the key way does not align vertically, then rotate cylinder back until it does. Then tighten the latch screw against it. DO NOT force mortice cylinders into vertical position.