How do I change the cabin air filter on my Audi A2?

I just bought a used Audi A2 and I'm not sure if the cabin air filter has ever been changed. What is the process for changing it and how often should it be replaced?

To change the cabin air filter on your Audi A2, first locate the filter housing under the passenger side dash. Remove the old filter and replace it with a new one, making sure it is facing the correct direction. It is recommended to change the filter every 15,000 miles or once a year.