Measure the inside width of your garage door with a tape measure.
Count the number of joints between the separate panels in your garage door to determine the number of strips needed. Cut 3/8-inch-thick foam weather strip to fit the length of the door.
Open the garage door slightly. Loosen the bolts on the hinges holding the bottom panel in position with the adjustable wrench. The bolts use elongated holes for attachment to make the panels somewhat adjustable in position. Once loosened, you can move the bottom panel slightly lower, widening the gap between it and the panel above.
Remove the protective backing paper from one of the cut foam weather strips and press the exposed adhesive side to the bottom of the panel above the lowest panel of the garage door. Attach the strip along the entire edge of the door panel.
Repeat the process with the next higher panel. Continue until all of the panels have a strip beneath them.
Realign the panels to their original positions by pushing each panel back upwards slightly and tightening the hinge bolts to hold them in their original positions. Open and close the door a few times to make certain the door operates smoothly. Make any adjustments needed to the panel position to close any gaps.