Abstract: A kit, for use with a building having a sectional overhead door and at least one vertically disposed strut for reinforcing the door against wind damage, unauthorized entry and the like, enabling quick installation in and easy removal of the strut from a door reinforcing position. Structure is are provided for releasably securing the top of the strut to the building and the bottom of the strut of the floor. Further, structure is provided to releasably secure the hinges of the sectional door to the reinforcing strut by using members having a finger portion for insertion into the hollow pin joining the hinge leaves at the knuckles. Structure is also provided for releasably securing the top and bottom of the strut to the top and bottom of the door. Similarly, apparatus for reinforcing an overhead door with a strut and releasable securing structure is also disclosed.