How can I take someone to court for a small claim?

A "friend" which I let borrow 400 dollars is showing no interest on paying me back and its been 6 months already. When I let him borrow the money I photocopied his license and beside it I wrote that I was letting him borrow 400 dollars and that he had to pay me back. We both signed it and also had one witness sign it. Is this enough to win or do I need more proof?