First of all, beautiful pics! Mine is just like it only a year older, 35K miles more and silver haha. Are you the bamaboy from soundillusions? I've seen you there before, know you had a badass setup in your blazer...
but anyways, getting the cd player out is quite easy, take a flathead screwdriver or something similar and pop off the plastic trim around the cd player/ac controls and whatnot. there will be some clips all around it, just be careful, it pops out hard but if you do it carefully it's really not that difficult. the cd player should slide right out...
I ran the RCA's behind the cd player out the right side of the dash then underneath the carpet to the back of the vehicle. I gave up at the second row seat and have them on top of the trim panels on the floor cuz i didn't want to have to take out the seats and get under everything...if that makes any sense...if not you'll see what i mean when you start to take it apart...
Right now I did the same thing with my ONE run of 1/0 gauge and ran it on the left side underneath the carpet to the second row seat where it's on top of the trim thingy to the cargo area. but yeah it would be difficult to get more than one run of 1/0 under there. good luck and nice truck!