Tail Lights on our Buick Leasbre

Its very simple, its part of the brake light housing, check the trunk, you may need to pull back the plastice peice on the inside rear of the trunk, like where the trunk lock locks into place, and might need to pull back some of the carpet, but the headlight housing should unscrew from the inside of the trunk and then the housing should pop right out and you can pull the bulb, let me know if this helps