Adjusting your car’s headlight aim should be left to a professional with the proper aiming equipment. However, you can make temporary adjustments for a lighting system which is critically out of adjustment.
Usually, each headlight has two adjusting screws: one on the top for controlling up and down movement and one on the side to control left and right movement of the light beam. There are several do-it-yourself ways to adjust the headlights.
The simplest method requires a blank wall 8 metres (25 feet) in front of the vehicle and a level surface in front of the wall. Adjustment should be made with the fuel tank half full and no unusually heavy load in the luggage compartment
Park the vehicle on the level surface 100 mm away from the wall.
Attach masking tape vertically to the wall in reference to the vehicle centerline and the centerlines of each headlight.
Now position a long piece of tape horizontally in reference to the centerline of all headlights.
Move the car straight back to a point 8 metres (25 feet) from the wall.
Starting with the dipped beam adjustment, turn the adjusting screws to get the brightest area of the light 50 mm below the horizontal line and 50 mm to the left of the headlight vertical line.
With the main beams on, the center of the light area should be vertically centered, with the exact center just below the horizontal tape line.
Since it may not be possible to position the headlight aim exactly for both main and dipped beams, if a compromise is required, keep in mind that the low beams are most frequently used and have the greatest effect on driver safety.