Replacing garage door extension springs is not a difficult task provided you know all the key steps.
How to change extension springs on a garage door.
If the extension springs are not the same length open the garage door and change the location of one of the s hooks so that when you close the door both springs are the same length.
Be sure the door is open and supported when doing this.
Enlist the service of one or more friends or family members to help with.
Open the garage door completely and lock it in the open position.
If both springs are the same length the garage door should be level across the floor.
How to install garage door extension springs.
To do this you will need to first detach.