To adjust headlights vertically or horizontally or both...Park the car on a flat, level surface. If possible have the car face a blank wall, neutral colors like white or gray work best. Avoid any internal light shining on the car.
Make sure the tire pressure is correct and the car is loaded as "normal"
Start with the car close to the wall (as close as you can) and facing the wall. Switch on dip beam, and mark the "cut off" with chalk. Now move the car 25 feet away from the wall.
Adjust the lights so the cutoff is below and to the left (to your discretion, but at least 3-6 inches imho) of the original marking.
This method will work for straightening the lights both vertically and horizontally.