Originally Posted by see link below

Pull open the right side trunk lining. Tucked back in there a little ways is a gray metal box with two cable harnesses going into it. One is the antenna (smaller), the other is the power, audio, and control for the XM receiver (bigger). Just take off the bigger connector. When you turn your radio back on, it won't see the XM, and should just skip past it. (That's what I recall it doing when I was messing around with adding a line-in connector.)