DIY, change the headlight on your Ford Mustang, made between the years 1999 and 2004. This replacement is simple and it won’t require tools. In some cases, if the tabs holding the headlight are too rusty, you might need a pair of pliers, but this replacement is designed to be made by hand, in less than 5 minutes.
So, open the hood of the car and go above the headlight. Here you have to remove by hand the two metal tabs that secure the headlight, seen in the image below. You have to push back on them first, to the rear of the car and then pull them up and out.
Now, you should be able to simply pull out and detach the assembly. But sometimes it is stuck in the back and you have to pull hard and firmly on it. By doing that you might scratch the paint on the bumper, so you should use a rag or a towel inserted between the headlight and the bumper, at the bottom side, to protect it. After you pull out the headlight, you have do disconnect two harnesses behind, seen in the picture below. The first is located at the edge of the assembly, to the exterior of the car, powering the side light bulb and the other one in the middle, powering the main headlight.
By unplugging those harnesses you are able to remove the old headlight and prepare to install the replacement. Move the light bulbs onto the new headlight if necessary. If not, install the new assembly reversing the steps above. This is all you need to do, if you plan to remove and replace the headlight assembly on your Ford Mustang, the model produced between the years 1999 and 2004.