A torsion spring is under enough stored tension to break bones or worse, and that's true whether the door is five years old or fifty. If you're comfortable replacing a roller or tightening a loose track bracket, that's reasonable weekend work. Spring replacement, cable replacement, and anything involving the winding bars is not - and on a door with original 1960s-era hardware, the wind cones and drums are often a size or thread pattern that doesn't match what's sold today, which is exactly the kind of mismatch that causes a spring to slip mid-job. If you're not sure what decade your hardware is from, that uncertainty alone is a reason to call rather than guess.