This tutorial will be similar to the one I did for 02/03's-http://www.clubwrx.net/forums/showthread.php?t=62506
What you'll need:
a set of oe fog surrounds
3' of brake duct- you don't need high temp ducting, regular will do- either 2 or 2.5"
2 duct reducers either 3->2.5" or 3-> 2"
2 plastic "connectors" found at the hardware store- don't really know what their application is (they were threaded on the inside)- anything that will fit into the duct end and then into the wheel well
four appropriate size hose clamps
The reducers will fit into the oe fog surround, you'll have to do a little bit of filing/dremeling for them to fit, squeeze the reducer and it will go in it will be snug