Reddit mentions of Lang Tools 5529A 4mm X 4.5mm Ford Headlight Adjusting Wrench

As a practical matter, you should pull the 08 and 11 manuals from here:

https://www.motorcraftservice.com/ownerinformation

The 08-11 manuals have instructions on aiming the headlights. The 11 manual also has some extra info as it was sort of Ford's "send-off" for fleet servicers, like the TPMS reset procedure, so it's good to have around.

In any event, if Ford's site goes down many years into the future and someone stumbles along this post trying to figure out how to aim the headlights, I slightly rewrote the instructions for myself as follows:

1. Park the vehicle directly perpendicular to a flat wall, 25 ft (7.6 m) away, at night.
   
2. Mark the centers of the headlights on the wall, as if you were aiming a laser beam out of the headlights straight and level onto the wall. To do so, on the wall, mark the horizontal centers of the headlamps at the base of the wall. It may help to mark the horizontal center of the vehicle as well. Then, measure the distance from the ground to the vertical centers of the headlamps. Mark that distance from the two headlight horizontal centers already on the wall. These two points should be where the headlights would point if they shot out straight and level from the vehicle.
   
3. Turn on the low beam headlamps and open the hood.
   
4. Look to the wall. The headlights should be showing a circular beam (if using aftermarket housings, it may be an X or a chevron or some other shape). The brightest area of that beam should be below the center points, so that the headlights do not shine any significant light above the points. It is a good idea to leave an inch or two between the brightest part of the beam and the center points to be safe. If your headlight beams are too high or low, you will need to adjust them vertically.
   
5. Check the horizontal alignment as well. The brightest area of the beam should be to the right of the center points. Combined, this will leave the brightest area of the beam to the lower right of the center points. If your headlights are not aligned horizontally to your liking, you will need to adjust them horizontally.
   
6. To adjust vertically, rotate the adjustment bolt on the outboard side of the light.
   
7. To adjust horizontally, rotate the adjustment bolt on the inboard side of the light.
   
   And for those who don't have a headlight aiming tool (extremely helpful), this is what I have.