1. Open the hood of your Audi 90, and support it with the hood stand. Loosen the bolt clamp on the negative terminal using a wrench. Lift the negative cable from the terminal.
2. Remove all the knobs and dials from the equipment on the front of the dash. Place them in a safe area, as you will need to reattach them when you reattach the dash.
3. Open the glove compartment, and remove the two mounting screws that hold it in place. using a Phillips screwdriver Locate and remove the rest of the screws on the lower dash assembly. Remove the glove compartment and the rest of the lower dash from the vehicle.
4. Pull the face plate from the front of the dash to gain access to the electrical components. Remove the mounting screws that hold the radio and instrument cluster in place. Unhook the electrical wiring from the rear of the components, and lift them both from the vehicle. Place the screws for the components in a safe area, as you will need to reattach them later.
5. Remove the rest of the screws attached to the upper section of the dash. Remove each panel one at a time until you have removed the entire dash. Take care not to damage the interior of the Audi.