Denny,
I adjusted my head lights last night, and I have a tip to add to your fine instructions:
Many floors are sloped, and outside there is all manor of grades and shapes. I accommodated this by taking a piece of string, set one end on the ground by the rear tire, put a few bricks on it, and then stretched the string out 25 feet beyond the front head light and moved it up and down so it just touched the floor at the front tire. The string was about 4 inches off the ground 25 feet out because the slope of the floor changed beyond the front tire. so I compensated by drawing my line one inch above the midpoint as measured from the floor.
Worked like a charm.
Kurt