tapping factory receiver

I'm trying to install my C-10 Kicker in my 1998 Durango. I recently installed new speakers (Alpine SD's) to the factory receiver (I just stripped the wires and connected the new speakers to the factory wiring). Now, to save myself a pretty penny and not having the subwoofer installed or buying a new receiver and wiring the entire truck, I would like to try and install it myself through the factory receiver. First question, is it even possible? Second question, if so, which wire do I need to tap into on the receiver's wiring harness?

Any input would be appreciated.

Thanks.