There should be two screws on the back of the headlight housing. They are silver I believe. One may or may not be under a plastic cap which can be difficult to remove.
Assuming your housings are the same as mine (which they should be), there should be one easy to reach screw and one harder to reach. The easy to reach one does the vertical aim, which is what you want. It is easy on the passenger side, but the driver side can be tricky with the battery in the way. I have done it with the battery still there, but if you need to take it out, go for it.