DIY, change the headlight assembly on your Buick Lesabre, the model produced in the years 2000, 2001, 2002, 2003, 2004 and 2005. You will require a flat headed screwdriver and a 10 mm socket wrench, with a ratchet and extension. This replacement should not take you more than 20 minutes.
In the beginning, after you open the hood of the car, you will have to remove two 10 mm bolts that secure the headlight assembly. They are located as seen in the picture below.
After you do it, you should pull out firmly the assembly, because it is also held by a metal knob, on the outer extremity. Behind it, you will come across the main electrical harness, as seen in the image below. Unplug it and detach the headlight completely. At this point you can also service the bulbs, by twisting their sockets counterclockwise.
Now, in order to install the replacement headlight properly, you might need to transfer the entire electrical harness to the new assembly. Use a flat headed screwdriver where is necessary and make the required replacements, then align the new headlight into the body of the car and secure it with the two bolts. This is all you have to do, in order to change the headlight assembly on your Buick Lesabre, the model made between the years 2000 and 2005.