How can I reset the MMI system on my Audi A4 if it is frozen?

I am unable to access any functions on my Audi A4's MMI system as it seems to be frozen. How can I reset the system and regain functionality?

Try holding down the MENU and RESET buttons simultaneously for 10 seconds until the screen goes blank and then release. This should force a system restart and resolve the frozen MMI issue.

If the above method does not work, try disconnecting the car's battery for a few minutes and then reconnecting it. This may also reset the MMI system.