Contour Enthusiasts Group Archives Forums Modifications Audio how do you hook up amp and subs to factory radio

i have a 2003 ranger with the six disc in dash i am gonna hook up a amp and two subs in my truck and i was wondering what i need to hook up. i have rca's and all the wireing. how do i go about hooking up rcas with out them there from factor. i think there is a box you can hookup so you can you rcas.