You have to remove the windshield and the plastic trim underneath it along with some screws and nuts. Check out this thread
http://www.kymcoforum.com/index.php?topic=10361.0The pictures show which ones you need to remove, make sure you remove the correct ones as shown, once you do that it takes a little bit of tugging to pull the front end off since they're locked into tabs. Actually I think you're right, there may only be vertical adjustment for the low/high beams. Here's a pic of the headlight assembly from the back. The silver piece with the phillips indent is the piece you rotate to adjust, each low beam and high beam has one next to the corresponding one it adjusts. And to answer your question in your original post, there is a rubber cover behind the headlight bulb which i'm sure you know of by now, I'm able to stuff the ballast and everything inside and pop the rubber cover back on with the cyclops adventure bulbs, not sure how large the other ones on the market are.