Given that this seems to be impossible to me, a mechanic with over 45 years of experience, and given that this situation can't possibly be a rare one, I am absolutely astonished that this topic hasn't been discussed in this forum at this point. I've tried following the instructions given in my Chilton shop manual, but am unable to pull the headlight assembly forward. Oh yeah:
1. It's definitely the bulb that's burned out, not the fuse. The driver's side bulb is still working.
2. I know how to align the releases so that the assembly should move forward.
I've read that one literally needs to remove the bumper facia to do this task. I've performed this task recently on a 2006 Lucerne, and I don't want to repeat the hours long experience. There must be a way to easily replace the low beam headlight bulb.

Can anybody tell me now to do this especially any tricks that might simplify the process? Thanks in advance.

 

I've checked out Youtube, and the videos are either horrible or the people making them didn't know what they were doing, or they left steps out.

 

Note that these instructions will apply to a range of models up to, but not including the 2010 models and beyond. Here we go, and also note that these instructions are a detailed description of what worked for me. Your mileage may differ:The Buick will need H11 light bulbs for both low and high beams as far as I am aware. That is, unless you've gone with a higher intensity bulb so that you can blind oncoming traffic and experience a head on collision.

For both the low beam and the high beam, the lights have a screw on cover and the bulbs are removed by a standard twist of that cover to the counterclockwise and replaced by a twist to the clockwise. The high beam cover is easy to get at but to replace the low beam bulb, you have to release the entire light assembly and push it forward before you can get at the cover to remove it and reach the bulb. What follows is a description of what I went through in order to accomplish this.

There are two locking tabs at the rear of the headlight assembly. They hold the headlight assembly in place. The inboard locking tab is made of white plastic. Pull that tab up just to the point where it releases. Pull too far and it locks again.

Next, locate the other locking tab which is metal and is located on the outboard rear of the headlight assembly. This locking tab is held down by a bolt you will need to remove with a 10mm wrench. Lift the metal locking tab just like you did the white, plastic one.

Lifting the two locking tabs up will eventually allow you to move the headlight assembly forward. But first:

There is no reason to completely remove the grill and the bumper fascia as some people are saying. You only need to loosen them a little so that you will be able to move the headlight assembly forward some. This is done by first removing two expansion locking pins, one that holds the little plastic strip down between the bright and dim lights and another one located inside a rubber bumper on the inboard side of the light unit.

To remove these locking pins, CAREFULLY pull or pry up the little tab in the center of the pin just like you were pulling a nail by the head. DON'T PULL IT ALL THE WAY OUT! Then pull the complete pin assembly out carefully and place it where you won't lose it.

Next, remove the pins holding down the shield which is over the radiator and remove the shield. Then remove at least three (to your left) of the four fastners that hold the grill assy to the radiator support.

Once freed this way, the top of the bumper fascia will now flex enough that you will have a little more space to move the headlight assembly forward enough to work it out of its locking sockets so you can get at the bulb covers and light pockets on the back side. When you firmly pull the light assembly forward, it will make a distinct "CLICK" when it frees itself from the housing tabs. You should now have barely enough room to do the job and replace the low beam bulb.

To replace this bulb, remove the low beam cover by turning it counter-clockwise. With considerable effort, you should now be able to remove the bulb by also turning it counter-clockwise. Detach the wiring plug from the bulb and discard the burned out bulb.

If you do touch the new bulb glass with your bare hands, you'll deposit skin oils which will create a hot spot on it the first time it's used. This will either cause the bulb to fail or at the least will drastically shorten the life-span of the bulb. If you accidently touch the bulb this way, wipe it clean with an isopropyl (rubbing) alcohol soaked paper towel and allow the bulb to dry. The best way to avoid this problem altogether though, is to wear rubber gloves while you install the new bulb.

To install the new bulb, attach the power plug to it and then put the bulb in the holder. Then give it a clockwise twist until it's fully locked in place. Replace the bulb cover and also lock it in place fully with a clockwise turn Test the headlights to make sure the new bulb works.

Align the headlight assembly tabs and push it back into place. Push down the locking tabs and replace the metal locking tab's bolt. In reverse, reassemble the reast of this mess designed by General Motors in an attempt to ensure that you can't do what should have been a simple task and so that you will instead need to have then do it for you at great cost. By visually examing how this monstrosity was laid out, it was easy for me to determine how Buick could have simply modified things a little so that anybody could have easily replaced their low beam headlamps when they burned out.

I am not a happy camper.

It you think this is bad, pity anybody owning a 2010 and newer model. They have to completely remove the bumper fascia in order to get at the headlight assemblies.