to reactivate my radio how do i enter the radio code do i just turn on the car and punch in the code or do i have to push something else?

 

It tells you in the same manual that contains the radio code.
You have to hit 2 buttons on the radio at the same time, then enter the numbers in with the 1,2,3,4 buttons on the radio.
I cant remember of the top of my head, search, or read your manual.

 

Thats assuming of course he has a manual and that his code is in there, unlike mine its not and i need to go to audi when i replace my battery so i can get my number, and yes its costs $100