Normally how they work is you open the door and insert the new key and then insert a setting pin to reset the lock and the combination pins will use the new setting.
How to change door locks to fit one key.
Once the new pins are in reverse the steps to reassemble the lock.
You ll have to remove the lock from the door for this option and bring the key that currently opens.
Having the combination changed is more affordable.
I don t recommend the you change it locks too many ways to screw them up.
I am a locksmith with 35 years experience.
If you are adding something like a deadbolt you will need to cut a hole with a hole saw which is a large drill bit.
In some cases door latch plate mortises might need to be cut or enlarged.
This is a high tech solution for your home to allow you to use a keypad at the lock or use your alarm system or wifi to open and close the lock.
Begin by removing the screws from the door knob on the interior side of your door.
If you have a window in or next to the door a lock with key cylinders on both sides is preferable as long as local codes allow and you keep a key within reach.
Use wire to secure this knob s key to the knob.
Insert the pins and reassemble the lock dump out the old pins insert the new key and use tweezers or small needle nose pliers to match the new colored pins to the color code on the special instruction sheet.
Wifi locks or keypad locks.
When drilling you want to drill half way through from one side and half way through from the other side.
Remove the two screws on the inside of the doorknob.
Remove the two screws from the latch plate on the edge of the door and remove the latch from the opening.
Slide the exterior half of the doorknob off while leaving the interior half of the doorknob in place.
Take the lock locking knob or deadbolt to the locksmith local lumberyard or hardware store.
Using a template that should be in the box with the lock you tape it to the door and drill the hole.
Prop the door slightly open.