How do I get the radio code for my 1986 325 BMW?

Just purchased 1986 BMW. I disconnected the battery and now the radio says I need a code to enter. I do not have owners manual. How do I get the code?|||you should be able to take it to your nearest dealer along with your proof of purchase and VIN number to the car and the dealer should be able to give it to you some dealers charge so might be an idea to ring them before you go|||call your nearest bmw dealer and they'll help u out