A) To open (release) jammed Circular (Knob) Lock
B) Step By Step Procedure to change Circular (knob) locksets
First you will have to remove the old circular lockset. Use a nail or tool provided with the lockset to deoress the knob (lever) catch hole and slide (pull) the knob off the spindle.
This is how the lockset looks like after you remove the knob (lever)
Remove the two screws that hold the lockset to the door.
Pull out the other end of the knob.
Remove the screws that hold the latch unit to the door frame. Then pull out the latch unit.
The old lockset is completely removed from the door.
To install the new lock. use a nail to depress the knob catch hold and slide the knob out from the spindle.
Put the latch unit into the side cavity. Push the lockset into the round cavity of the door. Make sure that the lock housing engages with the latch prongs and the retractor interlocks with the latch bar. This is to ensure that the latch would move in or out of the box strike whenever the knob is turned.
Depress the knob catch hole with a nail or tool provided with the lockset. Slide in the knob into the spindle. Install rose by snapping it in place or for some circular locks models, you just need to turn it clockwise until it touch the door. Your circular lockset is ready for use!