Luke, once you get the housing in the neighborhood, it's easy to make the final adjustment up and down. On the back of the housing you'll see a Y shaped groove with a silver metal sprocket at the bottom. The right sized phillips head can be used to turn this and you'll see the beam move up or down. Or look on the very back of the housing to find a metal disk with a small bolt head on it. Turning that with a pair of pliers does the same thing.

Mark