Hello everyone , i'm new in here and i need some help .

I have Audi A6 2005 with MMI basic plus , recently my cd charger broke down (all slot lights flashing , and the message for all CD1-6 unreadable , and all are empty).
Now i'm using cd navigation for playing audio cd.

Since i need to change chaarger and on the other hand I would like to play MP3 files from SD or USB , can anybody advice what to do ?
What changes can and should I do ?

My screen is small is red monochromatic
I have 8 button console with CD/TV button
CD navigation and CD Charger are in glow department

Many Thanks in advance