Swapping a single roller on a garage door yourself isn't unreasonable if the track is straight, the door is balanced, and you're only replacing a non-bottom roller, since those come out without releasing cable tension. The bottom rollers are a different job because they sit next to the cable drum and spring tension, and that's where we see the injuries. On a 1993-era door, there's a second problem: the track brackets are original too, and if a roller has been grinding for a year, it's usually bent the track slightly at the spot it failed. Replace the roller without checking the track and you'll be back out here in two months with the same noise. If you're set on doing it yourself, the honest advice is to check the track with a straightedge first. If it's bowed more than about a quarter inch, that's not a roller job anymore, and no new roller fixes a bent rail.