Replacing torsion springs is done with the door closed. You start by carefully unloading all of the springs (most standard-size doors have two; any broken spring will already be unloaded), using the winding bars. Then, you unbolt the springs from the central rod bracket, disconnect the cables from the pulleys, and loosen the pulleys and slide them off of the rod. Next, you swap out the springs, reinstall the pulleys and cables, and secure the inside ends of the springs to the central bracket. Finally, you wind up both springs (securing them with two setscrew bolts on the winding cones) and test the door for proper spring tension. Often, springs need an extra quarter-turn or two to get the door balance just right.
Since most yards entertain play activity including baseballs and other sporting equipment, it's no surprise that garage doors experience broken glass from time to time. Regardless of the cause, it's important to repair glass quickly, since broken glass in a garage is a safety issue, a security problem, and an invitation to every bird and insect in the neighborhood to take up residence in your garage. Fortunately, it's not difficult to replace a pane of glass. The techniques are exactly the same as for replacing glazing in a house window.
10.1 It is now time to wind the new springs, but before doing so, I recommend marking the shaft just beyond the winding cone. This is a final step taken to assure that you have installed the springs on the correct sides of the center bracket. Torsion springs always grow in length when they are wound in the proper direction. If your spring does not get longer as you wind it, you are winding it the wrong direction probably because it is improperly installed. We recurrently get calls about springs coming loose from the cones at about 6 turns. If this happens, switch the springs.