tapping into the aux In 1/8"
 

I have a 2010 Mazda5 and I want to hide my 1/8" aux in portable XM plug behind the panel. While it's easy to remove the cup holder and aux in/accessory power panel, I'm not sure what wires I will need to tap into. The aux in has 4 wires running into it, and I'm not sure about the best way to go from 1/8" audio cable to bare wire so I can make the connection. Any help is appreciated!

:D