Align the upper roller tracks by carefully lifting the door halfway. Lock it in place with two locking pliers, and install the supporting brackets on the back of the rails using 1-1/4 in. perforated angle iron (available at home centers and hardware stores). Install 1-1/2 x 1/4 in. stop bolts, with the threads to the inside of the track, at the end of each upper track.
Sears can fix almost any broken garage door opener, regardless of the brand or where you bought it. Trying to repair a garage door opener yourself can be dangerous because of the spring tension. The Sears technicians who repair garage door openers are experts; they have the knowledge and experience to repair the garage door opener correctly and safety.
Center and level the first section after you install the brackets. The door must be level even if the floor isn’t, so use shims under the section to level it. The rubber gasket on the bottom section will fill the gaps created by an unlevel floor. To hold the level in place, tape it to the section. To hold the section in place, lightly toenail a 16d nail into the frame and bend it over the section. Add brackets and rollers before setting them in place and stack one section on top of another, toenailing as you go up.
The power to your garage is out with the door shut, and you need to get your car out or you'll have to take a bus. You'll notice a cord—usually with a red handle—dangling down from the guide track that the opener uses to open and close the door. This is the manual override. Once pulled, it allows you to open and close the door with your own power in the form a little elbow grease.