First the lower door panel needs to be set up in the center of the doorway.
How to install overhead garage door.
Slant or slightly bend the nails to secure them in place.
The remaining panels and tracks are held in place with hinges brackets and screws.
Once the piece is in place tap nails partway into each jamb.
This old house general contractor tom silva shows how to assemble and hang a new garage door.
Set the bottom piece into position insert the bottom piece into the door frame and use a level to properly set the piece.
Tie the extension spring to the roller track then detach the cable from the bottom bracket with a pair of pliers.