I'll check to see if there were any instructions that came with the harness. It is fairly simple though. The RCA plugs plug into the corresponding RCA jacks on the head unit and the rest of the wire colors match up to the wire colors on the head unit. This harness bypasses the module in the dash (I guess that is a tuner module?) that is right under the glove compartment. But, if there are any instructions I'll take a picture or something and post it up.
Thanks!
Edit: Scratch that. Here is a .pdf to the instructions that was provided in the link I posted above:
http://a248.e.akamai.net/pix.crutchf.../120701857.PDF