I'm changing out the pulley on my 04 GTP. I was wondering how do I get the new pulley in place since the end of the pulley shaft does not seem to have anything to attach to.

There is a 8mm hole in the center of the shaft, You will screw in a threaded bolt there to pull the pully on.There might be a plastic plug covering the hole, You will need an install tool for the job, It is really easy with the right tools.
Bill