Xiter, you will have the manual soon, true, but it will not tell you how to dismantle the instrument pod to component level (Audi technicians only ever replace the entire unit).
When you have removed the pod from the dash, you will then have to use a great deal of care and common sense to get to the inside of the instrument cluster and you will then be able to see the sounder attached to the circuit board.
I would post a photo, but it means taking my dash apart, which I don;t really want to do at the moment, because there is nothing wrong with it!