How do you replace the headlight bulb located on a 1998 Geo Prizm?

Unplug the wire connector from the bulb, pull off the big black round rubber water seal, jiggle the metal locking pin (kinda like a mousetrap) to get it to open, then pull out the bulb. (On the passenger side, you probably need to unbolt the fuse box first to be able to reach). Installing the headlight is the same process in reverse. Make sure to put the water seal back on in the correct orientation (there's a little line that should be on the top). Takes maybe 10 minutes. GE 9003 HB2 bulb, can find at Walmart and elsewhere.