Remove the latch assembly doorknob.
How to change security door lock.
Remove the two screws from the latch assembly on the side of the door.
First remove the lock from your door following the manufacturer s directions.
Remove the screws from the old lock on the inside of the door.
Use a phillips head screwdriver to unfasten the two or three screws located on the inside knob plate.
Remove the strike plate on the door jamb as well.
If your new lock is the same brand and model as the old one you may be able to keep your existing latch plate and strike plate.
Do not skip this last step.
Most electronic locks come with two screws that you need to remove from the inner part of the door.
Check the back part to find the screws that are holding on the back cover.
Turn over the lock so its keypad faces downward.
You may also need to use a wire tool or a paper clip.