I finally got around to trying this repair for myself on my 1990 SC. All told, it took me about 4 hours, but I could probably do it in 1-1/2 to 2 next time. I have a few comments:
1. On my car with the early ABS system, it is a lot harder to get a wrench on the rear nut inside the engine compartment. You can do it, but you just can't see what you are doing. Unplugging some of the harnesses may help you get the wrench on the nut. But be patient and you will get there.
2. On the 89-92 cars, you have to move the windshield washer fluid reservoir, not the power box, to get at the front nut. That is very easy - there are two 8mm bolts holding it on. Don't drop the front bolt as you remove it - there's a heap of wires right there, plus the starter solenoid, which makes it hard to retrieve.
3. You don't need to remove the "flags" from the bolt heads. I did after I got them out of the car, but it wasn't really necessary.
4. You definitely can NOT use a 12 point wrench on those 2 bolts. They have round corners because of the "flagging" process.
4. I had trouble removing the pinch bolt from the spindle. It turns out that it is partially splined, so it doesn't want to slide right out. I used a ball joint press to remove it. That was overkill, but I tried a C-clamp first and that was underkill.
5. I also had trouble getting the UCA back into the spindle at the end of the procedure. I used the jack under the LCA to push the spindle up, but it didn't want to drop into place. What solved the problem was I used a prybar to push the UCA down, using a spring coil for leverage. This problem chewed up about an hour while I moved the jack here and there trying to figure it out.
6. I did the procedure without removing the wheel. It saved me time, but it did make it a little tricky to tighten the bolts at the end. With the car off the jack and sitting on the wheels as normal, it was tricky to snake my arm in there. What I did was to hold the ratchet inside the wheel well stationary and turn the ratcheting wrench inside the engine compartment. Forget about using a torque wrench - I had to guess at it.
Your write-up was very helpful. It made it look pretty easy - which helped me overcome my trepidation abotu suspension work. Thanks again!