Do not try to force the door open if it feels extremely heavy or binds
Unplug the garage door opener
Disengage the opener by pulling the emergency release cord
Get help from another person before lifting the door
Lift the door slowly and evenly from the bottom
Keep your hands and feet clear of pinch points
Secure the door in the open position with locking pliers or clamps on the tracks
Use a sturdy prop only if the door is stable and you can do so safely
Avoid using the automatic opener until the spring is repaired
Call a qualified garage door technician to replace the broken spring