Replacing cassette with DVD

Does anyone know how to wireup audio to a 9 pin aux cable on a gm/delco cd/radio. I am planning to remove the cassette completely and have the dvd audio run through the stock cd/radio when I press the aux button.

PAC makes an adapter that allows you to use the Aux input on GM factory radios that have one for things like you want to do. That would probably be your best course of action.