Lubricating rollers and hinges, tightening visible hardware, and clearing track debris are all fine to handle yourself, and on a door that's been in service since the early 1970s, that kind of basic upkeep is overdue more often than not. What isn't a do-it-yourself job is the spring itself. A wound torsion spring holds enough stored force to cause a serious injury if it lets go while you're working on it, and that risk doesn't go down just because the door is old - if anything it goes up, since you don't always know how much life is left in metal that's been cycling for decades. If the opener is tripping, reversing unexpectedly, or not sensing an obstruction the way a modern unit would, that's also not a wiring fix to attempt casually, especially on an older unit that may not have the safety sensors built in that newer code requires. Call it in for anything involving the spring or the opener's internals.