How to replace headlight bulb
{: ) Turn off engine and open the hood.
Remove the front wheelhouse liner. The wheelhouse liner is sometimes called the mud guard or the splash shield, whatever. Whichever side, say we begin with the front left(drivers). If you dont wish to remove the front left tire, just turn the wheels far to the right to gain enough clearance. Start removing all those push pins and #7mm screws. And you dont need to remove the whole liner and all the screws and retainers. . Just remove only those nearest the headlight and front bumper area in order to loosen the front half portion of the wheelhouse liner. Just enough for your arms to move freely inside.
At this point, try your hands to reach in for the rear of the headlamp. Work your hands inside to remove ccw the bulb cap, and next on the low beam bulb. Note the position before turning it counterclockwise to remove. Release the bulb from the headlamp assembly (turn counterclockwise) Disconnect the electrical connector. Just remember the positioning of the bulb so you can swiftly reinstall a new bulb.
Note: If you still need more clearance for better movement, you can (1) remove the tire. or (2) remove the 3 screws that secure the bumper to the body, and then pull bumper outwards to loosen.Try to reach in again. If still not possible for you, proceed with the next step.
Remove the front sight shield that is covering the headlamps from above. This is the plastic shield with seven pop up retainers. After removing the front sight shield, you will get a better view of the 3headlamp mounting bolts. The 4th one inside the wheelhouse liner.
Remove the 4 bolts of the headlamp assembly. Two on top, and one on both sides. Then pull the headlamp forward enough and try to reach in your hand to remove the bulb cover and then remove the bulb from its socket and connector. turn ccw to remove. Note also the bulb position before you remove it from its socket.
Still need more clearance? Remove the remaining pop-up retainers(6) thats supporting the front bumper fascia from above. It will be better if you have an assistant who can stretch out gently the loosened bumper on that particular side, while you carefully maneuver the headlamp assembly removal inch by inch. If in case still unlucky, or you if found later that the bulb connector is melted or burned, proceed furthermore and remove the headlamp assembly all the way.
A burned connector needs to be replaced and a new bulb installed, even if you find the old bulb not busted.
With all the parts removed, you wiill have a better view of all other components within that area, the park and signal bulbs, the horn, the fog lamp, so that the next time you need to work on them you'll have a better gameplan. You may even bypass some steps mentioned earlier It's a matter of practice. I know its kinda tedious job for many owners. Just imagine removing so many screws for one simple bulb. But if you'll be patient enough, and get the hang of it, you will be saving labor costs.and enjoy loving your Acadia.
I hope you remember how and where components were removed, so you wont be lost in the reinstallation. Okay ? goodluck. : )