That's interesting. I did the same job on Sunday morning, after 5 hours sleep and jet lagged having just got in from Europe. Perhaps it was the fatigue, but I didn't find the job particularly difficult. About 2 hours to take the old pump out, and 2 hours to put the new pump in. No problems encountered along the way. Now, my '93 model is a bit simpler, it has one less connection at the pump, as it lacks the oil-to-water cooler present on earlier m104 engines.
I found every allen head could be easily accessed using just a regular swivel (u-joint) and extension, or with a standard allen key. Shoot, the hardest part was getting the hoses off the old water pump in one piece - they really take a set after ten years!