How to change transmission oil on an Audi A4 quattro?

To change the transmission oil on an Audi A4 Quattro, start by lifting the vehicle securely and placing it on jack stands. Remove the transmission drain plug and allow the old oil to fully drain into a container. Replace the drain plug and refill the transmission with new oil through the fill plug, using a pump for easier access. Finally, check the fluid level with the engine running and ensure it's within the recommended range before replacing the fill plug.