Garage door springs come in two styles.
How to install garage door spring.
The doors with two springs are easy to replace.
A couple of carabiners can.
In the past extension springs were safer to install but didn t have containment cables running through the center of the spring.
Disconnect the spring from the track bracket and the spring pulley and disconnect the safety cable from one end.
Install the new spring reinstall the pulley and reconnect the safety cable and you re done.
Torsion see above which mounts on the header above the door and extension photo 1 which floats above the upper roller track.
The general process is simple and safe.