I can not access the bulb. The lens will not come

Normally accessed from the back shelf. It slides left or right to unlatch the cover. You may have LED bulbs in the unit, in which case the whole strip have to be replaced.

https://www.google.com/search?q=2012+buick+lacrosse+third+brake+light+replacement

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from inside the trunk looking up at the light First, gently work the gray, carpet like cover loose from the area around the tail light ,(this may give you a little trouble). Once you have done this, you will see three silver nuts. These must be unscrewed. The lower left nut must be accessed through a hole next to where the trunk lid fits. (The screws are permanently attached to the lens housing so will not drop into obscurity when the nuts are removed). After removing the nuts, GENTLY work the lens housing away from the car. You may need a screw driver to unseat the housing, but just be gentle.

You will find three bulbs inside the lens. The brake light bulb is on the lower right side. Simply pull the old bulb out and insert the new one.

Just reverse these directions to reassemble the housing.

Hi Edward-
The top brake light lens is held on with two size T25 Torx screws. You need a suitable size torx screw driver to remove (and again later replace the assembly) the two screws. Once the screws are removed (do not lose these), you can remove the entire lens assembly. You'll see the wires leading to the plastic bulb socket. The bulb socket twists off the assembly like a bayonet. Once the bulb socket is off, you'll be able to remove the bulb simply by pulling it straight out. Replace the bad bulb by inserting the new bulb and then reassemble your third brake light in the reverse order you removed it. Enjoy!

You can't remove the lens cover. The tail lights are molded as one piece. If you want to change the bulbs, there should be an access panel inside the truck box right behind the tail lights that gives you access to the bulbs. There are also screws to remove the entire tail light assembly if it needs replacing.

Remove screws for lens. You may have to access them from inside the hatch. Then pull out lens, then turn and pull out bulb and socket, Push and turn then pull bulb out.

High-Mount Brake Light NOTE: Depending upon the vehicle, the center high-mount brake light may be accessed from outside the vehicle, through the trunk, or through the passenger compartment.

1. Remove the center high-mount bracket light lens retaining screws.

Fig. 17: Use a screwdriver to unfasten the center high-mount lens retaining screws . . .


Remove the lens in order to get to the bulbs.

Fig. 18: . . . then remove the lens for access to the bulbs


Carefully pull the bulb away from its retaining clip contacts.

Fig. 19: Pull the light bulb from the retaining clips


Installation is the reverse of the removal procedure. Before installing the lens, make sure the brake light operates properly by having an assistant depress the brake pedal.

Frist check your fuses,if good replace the burn out bulbs .

most of the interior lights can be replaced by popping off the cover and pulling the bulb. usually there are just a few plastic clips that hold it on. as for the third brake light, there are 2 i believe t16 or t17 star screws that hold the lens on. once you have that off, the rest is obvious.

High-Mount Brake Light NOTE: Depending upon the vehicle, the center high-mount brake light may be accessed from outside the vehicle, through the trunk, or through the passenger compartment.

1. Remove the center high-mount bracket light lens retaining screws.
2. Remove the lens in order to get to the bulbs.
3. Carefully pull the bulb away from its retaining clip contacts.
4. Installation is the reverse of the removal procedure. Before installing the lens, make sure the brake light operates properly by having an assistant depress the brake pedal.

I'll post the pics here in a sec.
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you can take the cover off the light from inside the car there are either two clips on the side or just pull up on the light cover to access the bulb