To install a garage door, take important measurements such as the length of the door, its width and the distance from the top of the door to the ceiling; attach the weatherstripping to the bottom piece of the door; and then fix the piece in place using nails. Attach any necessary hinges and lift handles.
Use a level to ensure the bottom part is properly aligned. Use the manufacturer's specifications to assemble the horizontal, vertical and curved pieces of the track. Install the remaining panels, hammering nails into the appropriate side jambs to hold them in place. When done with the panels, install the rollers into the vertical tracks on both sides of the doorway. Don't press the rollers too tightly against the tracks, and fasten the hinges on both sections of the door using a power drill.
If your door has a third section, install it using a similar procedure to that of the first and second sections. With the tracks and the three sections in place, assemble the necessary springs as per the manufacturer's specifications. Lift the door the remaining distance to check whether the tracks are properly aligned. If they are, attach the springs to the pulley system.