Update: I buckled down and put the time in to fix it. The whole project ended up taking about 6.5 hours. I had to remove the top trim piece, as well as the 2 trim pieces just behind it so that I could access the roller hardware. My hardware was only accessible on one side of the door, so luckily I properly identified which way it was facing. I found this YouTube to be quite helpful:
https://m.youtube.com/watch?v=UFTkedcSSpsBy far the hardest part of the project was removing the trim gently without damaging it. It took me a good 3 hours to get the first piece off, it was secured with pin nails in 3 different planes as well as glue at the joints and lacquer on top. I was using a razor blade and a putty knife to gently pry, but ended up needing to get out a pocket knife to poke into the glued corner joint and then gently rock along the seam in order to get enough clearance to get the putty knife in.
Once I got the top trim piece off, I had to remove a decorative trim piece behind that and then an interior wood piece. Unfortunately the interior wood piece was secured with construction staples that for the life of me I could not get to come out (they’d been shot deep into the wood). Removing this last wood piece took over 2 hours! I finally got it off by prying so I had just enough clearance to get a metal-cutting blade in so I could saw through the staples.
Once the trim pieces were out of the way, it was very easy to just tighten up the bolts on the one side’s roller, as the wrench access was on the side that I had removed. Once the door was hanging evenly, it was still a little stiff to close so I lubricated the tracks with white lithium grease, which did the trick. It slides open and closed like a dream now.
In reassembling the trim, I used two screws to secure the interior wood piece so that it can easily be removed the next time the door needs adjusting. Then I just slid the decorative trim into place beneath that without nailing it (the wood fits in at angled joints so the nails were overkill to begin with). Finally, I set the top decorative trim into place with just the existing nails into the wall that were already in it, and didn’t nail it to the two interior wood trim pieces so that I can just take them out without needing to remove this top trim.
So the next time this pocket door needs adjusting, it will take me less than 30 minutes!