How do I change the Audi A4's air filter?

I've noticed my Audi A4's performance has declined and I suspect it might be due to a clogged air filter. How do I change it and improve my car's performance?

To change your Audi A4's air filter, follow these simple steps: 1. Locate the air filter housing under the hood of your car. 2. Open the housing and remove the old filter. 3. Clean the housing with a damp cloth. 4. Insert the new air filter and close the housing. Your car's performance should improve immediately.