Do it yourself, change the tail light assembly on your Toyota Sequoia, the model produced between the years 2001 and 2004. You will need a Phillips screwdriver and a 10 mm socket wrench. The replacement procedure is pretty easy but it will probably take you more than half an hour.
You can start after you open the back door of the car. With a 10 mm socket wrench, remove the two bolts seen in the picture below.
Now, if you grab and pull out firmly the tail light, you will be able to detach it. Behind it, you will notice the wires powering the light bulbs. You can twist the sockets of the bulbs counterclockwise, pull them out and separate the lens completely. Then you can change the tail light with a new one. But in some cases, you might need to change the lens and the harnesses with the bulbs. In order to do that, you will have to remove the silicone plate located on the floor of the trunk (see image below). You can do it by removing the six Phillips screws that secure it.
After you get rid of the retainers, pull up the plate. Then move your attention towards the tail light that needs replacement and remove the retainers shown in the image below. The first on top is a 10 mm bolt and can be removed with an appropriate socket wrench. The two plastic plugs marked with the blue arrows can be removed by hand, by simply pulling them out.
You might wanna do that to gain access behind that plastic panel, where you will locate the electrical connector powering the light bulbs (see next image). Insert your hand between the plastic panel and the body of the car and unplug that harness, in order to remove the entire tail light assembly.
In the end, after you make the needed replacements and repairs, install everything back reversing the steps above. This is all you need to do, if you wish to replace the tail light assembly on your Toyota Sequoia, the model from the years 2001, 2002, 2003 and 2004.