1998 Buick Century Owner's Manual - Page 293

If you find that the headlamp aiming needs adjustment, follow these steps: I NOTICE: Horizontal aimof the headlamp must be done first. Adjusting vertical aim first will result in incorrect headlamp aim. Driver's Side Headlamp Shown A. Vertical aim adjustment screw B. Horizontal aim adjustment screw 1. Start by opening the hood and locating the vertical and horizontal aim indicators. The aiming screw for the vertical aim indicator is at the center the of headlamp cover (A) and the aiming screw for the on horizontal aim indicator is the outboard side of the headlampcover (B). Passenger's Side Headlamp Shown B. Horizontal aim adjustment screw C. Horizontal block index plate D. Vertical aiming level 6-33