The stock wiring should work. You will need to plug in the gray plug. You also will have to unplug the amp. I don't remember the exact wiring set up but you can see from the picts in the link below I put in a scion unit with the same jacks as you.
The issue is going to be the Ipod cable.
see this link for details.
http://forum.ih8mud.com/80-series-tech/129577-scion-hu-install-ipod-control.html
You can do it with one hand. I did the install after I had surgery on my right hand for severed tendons.
John