Guys are saying not to reuse the springs, those springs are really tough! I've only did it once but last year on a rental house I replaced the door with another used door that was in much better shape.
Reused everything, and I mean everything. Put the new panels in, setup the cables, wound up the springs. Go have a beer.
I didn't even consider replacing parts as there just wasn't any money for it. Everything felt strong and very reusable.
Now I don't know anything about these springs or the safety of using old ones, I'm just telling you what I did.
Just sayin
Mm