A broken garage door handle is really a problem because the door is virtually impossible to open without one. Many garage door handles will break because the door is slammed to the ground with too much force. The handle screws will loosen and this makes the handle more likely to break.
Remove the screws that hold the garage-door handle to the garage-door panel with a Phillips head screwdriver and socket wrench.
Remove the broken garage door handle by sliding it out of the door handle bracket and through the garage door locking bars.
Match the handle to a new and similar part at the hardware store, and purchase the replacement. Or, find your replacement part through a garage-door parts supplier online.
Install the new garage-door handle. Place the gasketing (if any is supplied) on the door handle and then slide the locking arm through the slot inside the garage door assembly.
Line up the mounting holes for the screws with the holes in the garage door panel.
Slide the new mounting bolts through the mounting holes, gasket and garage door panel until they come through the other side.
Hand tighten the provided mounting buts onto the bolts. Then tighten with a ratchet.
Test to ensure the garage door locking arms engage when the handle is turned. If not, the handle must be removed and reinstalled, with the arms in the engaged position.