Before you repair a garage door, set it in the down position. 
You can do this with the lock. This will keep it from accidentally going up.
Required Tools and Materials
Safety goggles
Ladder
Wrench (1/2”, open end)
Wrench (7/16” open end)
Locking pliers
Garage door springs
Winding bars (1/2” round steel, 18” long)
A helper
Step 1
Detach the garage door opener using the safety rope. Wear your goggles and ready the ladder. If there are 2 torsion springs, unwind the one that still works.
Step 2
Put the ladder below the winding cone of the spring (the one not broke). The cone is usually directed away from the door’s middle. Start to repair a garage door by putting a winding bar in the cone hole. Press the bar in the roof’s direction.
Step 3
Put some pressure on the winding bar. Get the 7/16”. Remove the screws on the winding cone until you can move the spring. Unwind the torsion spring (both winding bars). The turn intervals should be 1/4. Take out one bar with the winding bar in the cone.
Step 4
Get the ½” wrench. Take out the bolts at the torsion springs (near the middle of the door). Set the ladder to the red cable drum. Let go of the screws. Repeat on the black cable drum. Take out the torsion tube and assembly.
Step 5
With the tube removed, you can proceed to repair a garage door. Remove the drums. Take out the torsion springs off too. Remember the setup of the cable drums and the springs. Put in the replacement garage door springs. Install the cable drums onto the tube. Get 10 inches on both ends of the tube. Secure the springs’ screws and the drums.
Step 6
Put the torsion tube in the red bearing and center plates (you’ll need someone to help you here). Put the torsion spring to the middle bearing plate. Fasten the bolts to the stationary cone and the middle plate. Secure them tightly.
Step 7
Put the ladder below the red cable drum. As you repair a garage door, you’ll need to set the cable from the bottom bracket to the cable drum. Lock it.
Step 8
Put some tension on the drum (this is where the cable is tightened). Lock the screws on. Hold the drum and cable and fasten in the pliers to the tube. The leverage should be against your house. Repeat this procedure for the other cable. With tension on the drums, put in the set screws.
Step 9
Put the ladder under one of the torsion springs. Use the winding bars and 7/16” wrench to fasten in the screws.
Step 10
Remove the lock from the garage door. Don’t open the door too fast. Adjust the spring turns if needed. Open and close the door a few times. If it’s okay, you can start using the garage door opener again.
Understanding how to repair a garage door is a complex matter. Make sure you and your helper know how to use these tools before attempting this.
