2004 6 disk cd changer aftermarket stereo swap

I am trying to install a new touch screen in my baby but am having a way harder time than I had anticipated. I bought two useless harness' that where supposed to work but didn't. Now I went out and bought a 100 Ft spool of 16 gauge speaker wire from Fleet Farm for a wopping 20 bucks. The problem I have now is figuring out which is the input side on the infinity amp and which is the output side of the infinity amp. Could anyone help me with this? maybe a picture or two to clarify?

Does your unit have rca cables for the an amp, if so I can look through amazon buys and check part number of correct cable.

Damn its an 04 ok ill look it up when I get home part metra 70-7003 the 8g. So ill have to do some digging.

I have been digging for about 2 hours a day after I get off work and still haven't found anything that refers to the 6disk changer. Any help would be GREATLY appreciated!