The one presented here is a.
How to replace garage door lock barrel.
Locate the lock cylinder on the interior face of the door.
With a barrel lock it s the cylinder that allows the locking and unlocking of a door.
Grab the pin with a pair of pliers to remove the pin from the shaft.
There are several types of cylinder locks.
Secure the lock from inside the garage with two retaining screws.
How to replace the cylinder lock on a garage door.
Place a nail over the pin and tap the nail with a hammer until you expose part of the pin.
Remove the nuts and bolts securing the lock bars to the cylinder with a wrench.
Secure the lock from inside the garage with two retaining screws.
However the bad news for you since you say that you ve not got a key is that you generally need a key to be able to easily take the cylinder out.
Remove the two screws that secure the outside lock assembly to the door with a phillips head screwdriver.
Remove the pin that secures the inside lock handle to the lock shaft in the center of the door panel.
This is a garage t handle lock if you have one and the barrel is not yet installed you can simply follow this video and slide it in if you need to buy gara.