Do it yourself, change the headlight assembly on your GMC Sonoma, the model manufactured in the years 1998, 1999, 2000, 2001, 2002, 2003 and 2004. This replacement can be done in less than 15 minutes, without any tools. In some cases, if the tabs that secure the headlight are stuck and you cannot pull them up by hand, you might consider using a pair of pliers on them, or a flat headed screwdriver.
First of all, open and secure the hood of the car and go above the headlight that needs repairs or you wish to replace. The assembly is held by two metal tabs, like the ones shown in the image below. They are designed to be pulled up simply, with your bare hands.
After you do it, you will be able to release the headlight. Behind it, you will come across its plugs and light bulbs, as you can see in the picture below. The new headlight usually comes equipped with the main light bulbs, that have connectors. The other light bulbs must be moved from the old assembly to the new one and can be removed easily, by twisting their sockets counterclockwise.
So, make the required replacements and install the new headlight, reversing the steps above. This is all you need to do, if you wish to remove and replace the headlight assembly on your GMC Sonoma, the model made between the years 1998 and 2004.