one pair of winding bars 1/2" diameter cold rolled steel 18" in length (can be purchased at most hardware stores in 36" lengths and cut to 18" to make a pair)
This page was written by Pro Door Supply for instructional purposes only, garage door springs are
under high amounts of pressure and can cause serious injury if not handled properly. Pro Door Supply
accepts no responsibility of personal injury based on this information, you should consider your own
abilities/limitations before doing this project.
Step 1. Removing the tension from the garage door springs and remove from center bearing plate.
Removing the tension is very simple, you will need a 3/8" wrench and a pair of winding bars for this part. Put a winding bar in the
cone and use the 3/8" wrench to loosen the set screws, as the set screws are loosened the force on the winding bar will increase. Once the set
screws are loose, slowly let the winding bar down to the door and let it relax there. You should have something to rest the bar onto other than
the door itself, if there is a strut in place there is no need for additional "padding" if not use a short 2x4 to prevent scratching or denting
your door.
Slowly unwind the garage door spring using the winding bars one quarter turn at a time.
as you bring the winding bar down to the door, place the other winding bar in the next hole on the winding cone, once it is in place remove winding bar at the bottom
and slowly bring down the next. Repeat the process until all the tension is removed from each of the springs on the garage door.
Do not remove springs from the center plate until tension is removed
Next Step is to remove the springs from the center bearing plate. For this you will need two 9/16" open end wrenchs. Using the wrenchs remove the two bolts holding the springs to the center plate
After Removing the two 3/8" bolts holding the garage door springs to the center plate, slide the springs slightly away.
This will be helpful later on when you slide the torsion shaft to one side or the other you can easily grab the spring without having to get off the ladder.
Step 3. Loosen the cable drums and slide the torsion shaft.
Using the 3/8" wrench loosen the set screws on the cable drum and slide it inward.This will be helpful when sliding the torsion shaft back and forth the cable drum won't interfere.
After loosening both cable drums it may be helpful to use a flat file to remove the burs (where the set screws left a dent) from the torsion shaft. Otherwise the burs may stop the torsion shaft from sliding back and forth.
Slide the torsion shaft one way or the other until it comes out of the end bearing plate.
Slide the old spring off the end of the torsion shaft, Slide the new spring in place and put the cable drum back on, repeating the process on the other side if you are replacing a pair of garage door springs.
After getting the new springs on, start reversing this process by putting the cable drums back on the torsion shaft. and sliding the torsion shaft back into the end bearing plates.
Pay careful attention to which spring goes on which side.Garage door springs are wound like threads on a bolt either left thread or right thread, hence the right wound and left wound. The right wound spring will go on the left side of the center bearing plate as you are standing on the inside of the garage looking out. The left wound spring will go on the right hand side of the door as you are standing inside the garage looking out.
Step 5. Setting the cables and drums.
Once the cable drums are back on and the torsion shaft is back in place in the end bearing plates, slide the left side cable
drum to the end bearing plate (always tighten the left cable drum first). Put the cable back in the notch in the drum and tighten the set screws using a 3/8" wrench.
After you have the set screws tight, roll the drum with your hand until the cable is tight and place a vice grips on the
torsion shaft to prevent the cable from unspooling.
Double check the cable to make sure it is resting in the outer most groove on the cable drum.
The photo on the left shows a cable drum that has been set, but has a space between the end bearing plate and the drum.
This is a common problem and will cause a number of problems that won't be covered right now.
The picture on the right shows one that has no space and is the correct way to set your cable drums.
before you go up the ladder to tighten the springs make sure you put a vice grips on the track right above a roller.
Any roller will work as long as the vice grips are placed so the roller cannot move upward. This will prevent the garage door
from rolling upward while your in the process of tightening the springs.
now fasten the springs back to the center bearing plate and start re-tensioning your
garage door springs the same way you removed the tension but in reverse order.
After you are done don't forget to move the vice grips from the torsion shaft and the garage door track.
Some Uselful things to know about replacing your garage door springs
as a rule of thumb a 7 foot tall garage door has 7 1/2 turns on each spring and an 8 foot tall garage door has 8 1/2 turns on each spring.
adjust your springs in 1/4 turn increments without going below or above your starting point.(you may have the incorrect spring if you need to go that far)
run the door by hand when finished, it should balance on its own in the middle, on the ground, and fully open
never use your opener to open the door while one or both of the garage door springs are broken
your springs are on the wrong side if you can only get 4 or 5 turns before the coils slip around the winding/stationary cone
Removing the tension is very simple, you will need a 3/8" wrench and a pair of winding bars for this part. Put a winding bar in the
cone and use the 3/8" wrench to loosen the set screws, as the set screws are loosened the force on the winding bar will increase. Once the set
screws are loose, slowly let the winding bar down to the door and let it relax there. You should have something to rest the bar onto other than
the door itself, if there is a strut in place there is no need for additional "padding" if not use a short 2x4 to prevent scratching or denting
your door.
Slowly unwind the 
Next Step is to remove the springs from the center bearing plate. For this you will need two 9/16" open end wrenchs. Using the wrenchs remove the two bolts holding the springs to the center plate
After Removing the two 3/8" bolts holding the 
Using the 3/8" wrench loosen the set screws on the cable drum and slide it inward.This will be helpful when sliding the torsion shaft back and forth the cable drum won't interfere.
After loosening both cable drums it may be helpful to use a flat file to remove the burs (where the set screws left a dent) from the torsion shaft. Otherwise the burs may stop the torsion shaft from sliding back and forth.
Slide the torsion shaft one way or the other until it comes out of the end bearing plate.
Slide the old spring off the end of the torsion shaft, Slide the new spring in place and put the cable drum back on, repeating the process on the other side if you are replacing a pair of 
Once the cable drums are back on and the torsion shaft is back in place in the end bearing plates, slide the left side cable
drum to the end bearing plate (always tighten the left cable drum first). Put the cable back in the notch in the drum and tighten the set screws using a 3/8" wrench.
After you have the set screws tight, roll the drum with your hand until the cable is tight and place a vice grips on the
torsion shaft to prevent the cable from unspooling.
The photo on the left shows a cable drum that has been set, but has a space between the end bearing plate and the drum.
This is a common problem and will cause a number of problems that won't be covered right now.
The picture on the right shows one that has no space and is the correct way to set your cable drums.
before you go up the ladder to tighten the springs make sure you put a vice grips on the track right above a roller.
Any roller will work as long as the vice grips are placed so the roller cannot move upward. This will prevent the garage door
from rolling upward while your in the process of tightening the springs.