How do I replace the alternator on my Audi A2?

I recently noticed that my Audi A2's alternator is showing signs of failure, including dim headlights and difficulty starting the car. I want to replace it myself, but I'm not sure where to start. Can someone guide me through the process?

First, make sure to have all necessary tools and replacement parts ready. Jack up the car and remove the negative battery cable. Loosen the bolts on the alternator and belt tensioner, and then remove the belt. Disconnect the wiring harness and remove the old alternator. Install the new alternator and reassemble everything in reverse order.