1994 GMC Other Headlights

GM has a number of different designs but you should not have to remove the lamp housings. Look for a pair of wires behind the bulb that have to be squeezed to release them, then pull the bulb out. It will come out a little hard because there's a rubber o-ring to seal out moisture.

There could also be a plastic ring that has to be turned counter-clockwise a quarter turn, then pulled away from the housing.

Be sure to not touch the glass part of the new bulb. Fingerprint grease will burn through it from the high heat and cause an early bulb failure.