I watched the tech do the compressor replacement and it was not all that hard.

First off you will have to go to a shop to evacuate and collect the refrigerant, otherwise you will have to dump it to the atmosphere, which is bad according to the EPA. .

My tech removed the cover underneath the front bumper so he could work from the top and bottom.

There is a rubber pipe from the engine to a cannister behind the headlight, looks like an EGR thing, which you should remove. The compressor was removed from the top so this line was in the way.

Remove AC belt, the belt tensioner is leveraged out of the way by inserting the appropriate sized allen wrench into the front of the tensioner pulley and just pushing the pulley in the appropriate direction.

Then you can unplug the harness and start removing the block fittings on the compressor.

Then you can start removing the compressor mounting bolts.

Then move the AC lines out of the way and you can pull the compressor out.

As mentioned it came out from the top.

Pretty much reverse to install.

Do take a look at your belts and the system o-rings while you are at it. I just re-used all of mine since they were still in good shape.

I think the 04's use a Calsonic Kansei CSV 717 compressor, the earlier models use a Denso. My 04 3.0 had the Calsonic.