I'm looking to redo the interior of my 2005 chevy equinox FWD, 3.4L V6 which would require me to change out the wiring that I believe is called the chassis wiring harness but I'm not sure and thats what I need to know.

I need the name of the type of harness that connects to the radio, temperature controls, power windows switches, speedometer, and steering wheel controls(cruise control and radio/volume controls).

Also, does anybody know where I can find a good diagram or instructions on how to install the harness and the level of difficulty 1 - 10... 6 being extremely hard.