Disengage the opener from the door.
How to instal a garage door spring.
Some garage door openers have a neutral position for the trolley disconnect.
Garage door springs come in two styles.
You may need to use a 2x4 or some other object to pry the garage door open.
Use locking pliers or a c clamp to secure the door to the track to keep it from opening when you release the tension on the springs.
A couple of carabiners can.
A pair of new springs cost about 25.
Torsion see above which mounts on the header above the door and extension photo 1 which floats above the upper roller track.
Unplug the garage door opener and clamp the door to the track.
The doors with two springs are easy to replace.
Disconnect the garage door opener so the door remains closed.
This can still be done when only one extension spring is broken.
Weigh your garage door.