1. Turn on the radio and press the "MENU" button.
2. Use the arrow buttons to select "SET UP," then press "OK."
3. Select the "CODE" option and press "OK."
4. Enter the unlock code using the number buttons, then press "OK."
5. The radio will confirm the code and start playing.
Note: If you do not know the radio's unlock code, you can find it in the owner's manual or contact your BMW dealership.