Need help with wireing DVD to Nav

I have the OEM Nav unit and I want to get a DVD player installed to play on the front Nav screen. I have a video switcher that came from another car that was playing DVD's and TV on a video screen so, what I have should work. I need to know what wire to splice in to for video and how to get behind the console in to it. I also need to get in to the AUX Audio some how to splice in to that wire. I was thinking while I'm in the AUX audio I should add some kind of a booster to pump up the AUX volume. If anyone has any pics or a link or has some great ideas I would love to hear them. I found this on my search but, it was only for the plug-N-play connection. http://www.clubarmada.com/forums/showthread.php?t=7779

Thanks,

Eric