How do you change a tumbler on a garage door?

On the inside depending of the age of the door. Some you have to take the inside handle off, and the tumbler is held on with 2 bolts. Some with a solid locking bar have the inside latch above the lock bar. This has 2 or 4 screws holding it on depending of model. Under this should be a small plate with 2 bolts holding the lock in. If the lock tumbler is in the handle the whole handle is changed.