Some of this you can do yourself. Clearing the tracks, wiping down and lightly lubricating the rollers, checking that the door reverses when it meets resistance - all reasonable for a homeowner to handle on a Saturday morning. What you shouldn't touch is the torsion spring itself. On a door this age, in a double-car size, that spring is under enough tension to break a bone or worse if the winding cone slips, and the tools to do it safely aren't something most garages have lying around.
The other thing DIY won't catch: cable wear that's invisible until it's not. A fraying cable on a 35-year-old system doesn't always show from the floor, and it's usually paired with a spring that's also near the end of its cycle count. That combination is exactly what a maintenance visit is built to find before it turns into a door that drops.
If you want the tracks-and-rollers version done yourself and just want us to handle the spring and cable side, say that when you call - we're fine splitting it that way.