Per the manual, each bulb has two adjustments - one for vertical (most common adjustment) and one for horizontal. The instructions are on p80 of the owners manual. I covet my owners manual because the dealer couldn't find it when I took delivery and I really wanted to have it for my new baby.
Anyway - if you look at the back of each headlight, from the riding position, with the bulb connector as the center of a clock face, the two adjusters are at 4 o'clock and 10 o'clock for the right side bulb and at 2 o'clock and 8 o'clock for the left side bulb. (Times are approximate.) They have a hex head (use 8mm or 5/16 socket) and are light colored metal.
The 4 o'clock (right side) and 8 o'clock (left side) are the vertical adjusters. The manual advises to adjust the horizontal first, then the vertical so there might be a little interaction between the adjustments.
Again, I found that it took a surprising amount of turning to see much change. As long as there is enough range, that is a good thing, I think.
2004 dl650-the urban warrior.
2007 R1200RT - the highway beast