Help with Line-In to '01 Monsoon System

I made the stupid mistake of getting the PAC AAI-GM9 line-in kit for my '01 Monsoon HU in my Camaro RS. I hadn't realized that I didn't have the required slave unit for it. Short of finding a slave or getting the right adapter, anyone have any ideas? Any pins that can be shunted to trick the HU into switching to AUX?

Thanks in advance.