We'll say this plainly: if the door is off the track and there's still tension on a spring, leave it alone. A torsion or extension spring under load, sitting on a door that's no longer running true in its rail, can move without warning when you touch the wrong bolt. That's not a scare tactic, it's just how the hardware works. If the door is down and the opener won't budge it, or one side of the door is hanging lower than the other, that's a job for someone who does this daily, not a Saturday project.
What you can safely do yourself is the diagnostic part: look at the rollers, see if one side jumped clean off the rail or if the whole track is bent away from the frame, and note whether the door was moving under power or by hand when it happened. That tells us a lot on the phone before we even get in the truck.