Ok, I just did all of this a few days ago.

The best way to run the power wire from the battery to the amp is along the passenger side at the bottom there is this rectangular foam thing with wires coming out, take the foam out and poke a small hole in that and feed the wire into the car from the outside. This is kind of difficult, but it is a good way. then run that wire along the passenger side under the carpet, take the door sill off first, then back and under the back seat and into the trunk.

The remote wire to turn on the amp can interfere with the power cable sometimes so they are supposed to be separated, i don't know how big of an issue this is, but anyways i ran that along with the right and left channel rca cables along the driver side in the same way.

As far as getting the trim off to get to the head unit there are two screws by the carpeted part of the cover under the steering wheel, take those out and take that part off, then you have to pry the trim around the dash off, it just clips in. I used a panel remover tool i got from napa for like $5, it worked pretty well. Then un-hook the fog light switch b/c that is still connected. There are two screws that hold the radio in and that is it.

let me know if u have any more questions, i'm still working on mine but i think i have it pretty much figured out. I still need help with mounting the sub and the amp tho.