Chevrolet 1998 Express Van Owner's Manual page 272

Headlamps
You have either a sealed beam headlamp system or a
composite system.
Sealed Beam Headlamps
I
2. Unplug the lamp assembly from the connector.
3. Install a new headlamp.
4. Reverse the previous steps to reinstall the headlamp.
1. Remove the four screws from the headlamp retainer.
Pull the retainer out and set it aside.