If you are planning to install a garage door opener to your door, then it’s a very good idea that you remove the lock you currently have. This is to prevent accidental locking that could damage your new opener.
To remove the lock, you should make sure that the garage door is closed fully. You will find a metal pin which is securing the inside T-handle, which you need to pull out. Then pull the lock bar plate from where the T-handle was mounted.
After you have removed the lock bar, you need to remove the two screws securing the front lock to the garage door. After you have disconnecting the lock bar and it’s guides from the door panel, you can pull the outer lock assembly from the door (outside).