Thats under the resonator, and below the area of the coil pack... Right past that hose there is a metal fasoner... That has 3 bolts on it.. 2 on top, one on bottom... Take those three bolts off... Pop off the houseing and pop out the old thermostat... Put the new gasket on the new stat. pop the new one in, close up the hose bolt it back on, have a beer, your done...
A couple of sidenotes:
Put a large pan under the area of the houseing... a lot of coolent will leak out, and buy some 50/50 Coolent to re-add.
