The Audi A4 is a high-performance four-door sedan with a space-frame chassis. This means the various body panels are attached without welding and can be removed with just a few tools. A screwdriver and a socket wrench will be all you need. Of course, since it is an import from Germany, the A4 has metric bolts, so make sure you have some metric sockets before your start. Using the wrong sized socket can mean "rounding" the bolt heads and that's not good when it's time to screw them in or out the next time.
Although not really necessary, removing the wheel does make it much easier to access the wheel well to remove the interior fender fasteners. What works best is using the car jack to lift the A4, remove the tire and then lower the car onto a strong jack stand. These are available from all auto supply stores. Make sure the stand supports the A4's frame. The wheel well is now open and the car is securely supported.
Removing the fender is a matter of removing all the fasteners (bolts, screws and clips) around the fender's edge. If you're removing the front fender, you'll have to go inside the engine bay to get the interior fasteners. If you're removing the rear fender, there will be fasteners inside the trunk. Also, inside the wheel well are fasteners securing the fender to the frame. If It's the front fender check underneath behind the headlight for the fasteners. The same is true of a back fender--check behind the taillights.
Don't ever force or try and pry the fender. If the body panel is free to move then check the location where it is still secure. Look for small fasteners that were undetected the first time around the edge.
Although not extremely heavy, the A4's fenders are rather cumbersome. It may be best to ask someone to help lift and remove the fender from the frame. Remember to never pull the entire fender out away from the car. Always start by lifting the fender up. Once up an inch two, allow the lower half of the fender to swing out and away from the car. When this is done lift the entire fender up and away from the car.
Once the fender is removed, try and set it down flat with the painted side up. Cover with a heavy cloth or even some bath towels. This will prevent an errant tool or shoe to damage the finish. Also, set the fender down in area away from any foot traffic, children or pets. The farther away from anyone the more likely it won't get marred.
