What do you need to do to allow you to change a dipped headlight bulb in your a4 avant 2002drivers side?

Answer

You need to remove the headlight assembly. Pop the hood. There are four bolts. Two are right up front on the sill, and very easy to get to. One is down behind at the right and very hard to see. You'll need a T30 torx screwdriver with at least a 6" blade. The fourth one is the aiming screw, so take care with that, as you'll need to put it back close to where it was. The pros would turn the working headlight on, and mark the throw on the wall to make this easier. DON'T remove the two back bolts. They only need to be loosened. Once the back bolts are loose and the front ones are off, you can slide the whole assembly forward. You can disconnect the electrical at that point, and pull the whole unit all the way out, or you can reach around and do it in place. I recommend the former... Once you have access, there is a small clip holding the back access hatch to the light assembly. Open that up and take it off. Pull the electrical connector off the lamp you're replacing and push in-and-over the metal clip holding the light. The lamp is now free. Pop the new one in (it'll only fit in one orientation) and replace the clip and electrical. CAREFULLY replace the hatch, making sure the seal is tight and correct. Reverse the process. Be careful when sliding the assembly in and out to make sure you don't scratch the bumber paint (or better yet mask it off before you start).

That's it. It is a 15-minute job, but you have to have the right tool (T30 screwdriver) and a bit of confidence.