I found this online and have been wanting to post a how to on aiming headlights, but since my truck is in Houston and I'm in Mobile this will have to suffice for now. My headlights need a little more adjustment after my leveling shackles were installed, I dialed them down but I think they need to come down a bit more. I realize that this write up is for a car and the adjusters are way different from what our trucks have but use it as a guideline and it should help you get the job done. Anyway here goes what I found.
Source: Automedia.com
Begin by finding a level surface and a vertical garage door or wall. Park the vehicle close to the wall and mark the lights' horizontal centerlines with masking tape.
Next, mark the low beams' vertical centerlines. For better precision, stand behind the car at its center point and, looking through the back window, guide a helper in marking vertical dead center. Marking the vehicle's centerline is also helpful to verify side-to-side alignment.
Park the vehicle on a flat surface 25 feet away from the wall, pointing straight ahead. Use the lights' horizontal- and vertical-adjusting screws to position the low beams' intensity zones two inches below and to the right of the taped centerlines. (Trim ring removed to show adjusters.)
Adjustments can normally be made without removing any parts. Turning the top adjusting screw clockwise raises the beam and vice versa. Similarly, the side adjuster moves the beam left and right.
High beams' "zones" should be below the line and vertically centered in relation to the vehicle's centerline (not marked with tape in this example). Here, the right-side high beam needs to come inboard. When in doubt, be courteous and err your aim low and to the right.
Source: Automedia.com
Or, how to maximize visibility without blinding other drivers
Tom Morr / autoMedia.com
How many times have we all been blinded by an oncoming vehicle and flickered our high beams, only to have the other driver melt our corneas by responding with their brights? The conclusion: Those low beams are jacked up (both literally and figuratively).
Causes Those low beams are jacked up (both literally and figuratively).
Headlights can become misaligned in many ways. One of the most common is when the person replacing a bad light inadvertently turns the adjusting screws instead of the retaining fasteners. Fender-benders and other front-end damage can also cause lights to become askew, as can carrying heavy loads in the rear quarters (which is why several upscale SUVs now have automatic load-leveling suspension systems).
Many repair shops will check and adjust headlights for a modest fee. However, the process is straightforward enough that the average do-it-yourselfer can save both time and money by following the steps shown here. Although special products are made specifically for correct headlight aiming, the method here doesn't require any proprietary know-how or materials—just masking tape, a tape measure and a screwdriver. Incidentally, most repair manuals recommend checking headlight adjustment every 12 months and any time a lamp is replaced or front-end damage occurs
Begin by finding a level surface and a vertical garage door or wall. Park the vehicle close to the wall and mark the lights' horizontal centerlines with masking tape.
Next, mark the low beams' vertical centerlines. For better precision, stand behind the car at its center point and, looking through the back window, guide a helper in marking vertical dead center. Marking the vehicle's centerline is also helpful to verify side-to-side alignment.
Park the vehicle on a flat surface 25 feet away from the wall, pointing straight ahead. Use the lights' horizontal- and vertical-adjusting screws to position the low beams' intensity zones two inches below and to the right of the taped centerlines. (Trim ring removed to show adjusters.)
Adjustments can normally be made without removing any parts. Turning the top adjusting screw clockwise raises the beam and vice versa. Similarly, the side adjuster moves the beam left and right.
High beams' "zones" should be below the line and vertically centered in relation to the vehicle's centerline (not marked with tape in this example). Here, the right-side high beam needs to come inboard. When in doubt, be courteous and err your aim low and to the right.

