Buick LaCrosse Owner's Manual page 370

7. Locate the vertical headlamp
aiming screws, which are under
the hood near each headlamp
assembly.
8. Turn the vertical aiming screw
until the headlamp beam is
aimed to the horizontal tape line.
Turn it clockwise or
counterclockwise to raise or
lower the angle of the beam.
9. Make sure that the light from the
headlamp is positioned at the
bottom edge of the horizontal
tape line. The lamp on the
left (A) shows the correct
headlamp aim. The lamp on the
right (B) shows the incorrect
headlamp aim.
10. Repeat Steps 7 through 9 for
the opposite headlamp.