I have a 12 Sierra that had the factory XM installed. I don't want to re-run new wires for a new antenna when i have a perfectly good antenna and tuner from the factory. i purchased a jvc 130bt double din to install which is sirius ready, i already have a the prc-32 in my truck for my pioneer im replacing. is there any how-to's or anyone know how to hook up a aftermarket radio to factory installed xm? Thanks.