1997 Ford Aerostar Owner's Manual - Page 273

NOTE: Do not disturb the aim adjusting screws. 5. Pull the headlamp away from the vehicle and remove the electrical connector by pulling rearward. Unsnap the bulb retaining wire and carefully remove the bulb assembly from its socket by gently pulling it out without turning it. 6. Installing the headlamp bulb 1. With the flat side of the bulb's plastic base facing upward, insert the glass end of the bulb into the socket. You may need to turn the bulb left or right to line up the grooves in the plastic base with the tabs in the socket. When the grooves are aligned, push the bulb into the socket until the plastic base contacts the rear of the socket. 274