2003 Buick LeSabre Owner's Manual - Page 305

4. Turn on the low-beam headlamps and place a piece of cardboard or equivalent in front of the headlamp not being aimed. This should allow only the beam of light from the headlamp being aimed to be seen on the flat surface. Notice; Do not cover a headlamp to improve beam cut-off when aiming. Covering a headlamp may cause excessive heat build-up which may cause damage to the headlamp. 5. Turn the vertical aiming screw (C) until the headlamp beam is aimed to the horizontal tape line. The top edge of the cut-off should be positioned at the bottom edge of the horizontal tape line. 6. Repeat Steps 4 and 5 for the opposite headlamp. 5-54