How do you change a high beam bulb in a 1991 GMC sierra?
You have to take the grille off of the truck. Its easy just four screws on the top, one about center of the grille and three clips on the bottom. Then there are four bolts holding the headlight assembly on, remove them take the entire assembly off and you will be able to get tho the bulb. My 1991 GMC also has a hidden one top center in grill, One bottom center in the grill and one behind each parking light. Not a lot of fun after all, it had to be wiggled and coaxed into clearing the bumper and head lights too. Couple of hours to put new assymblies in.