Park your car on a level surface, about 10-15 feet away from a wall or garage door.
Turn on the low beam headlights.
Open the hood of your car.
Locate the headlight adjustment screws. On the S40, there are two adjustment screws for each headlight, one for vertical adjustment and one for horizontal adjustment. The vertical adjustment screw is located on the top of the headlight assembly, while the horizontal adjustment screw is located on the side of the assembly.
Use a flat-head screwdriver to turn the adjustment screws. To raise the low beam headlights, turn the vertical adjustment screw clockwise. To lower the headlights, turn the vertical adjustment screw counterclockwise. To move the headlights left or right, turn the horizontal adjustment screw clockwise or counterclockwise, respectively.
Continue adjusting the headlights until they are aimed properly. The low beam headlights should be aimed so that the top of the beam is level with the center of the headlight assembly. They should also be aimed so that the left edge of the beam is about 2-3 feet to the right of the center of the car.
Once the headlights are adjusted properly, close the hood of your car.
