First you will want to remove the Air filter housing from the throttle body.
Next you will need to disconnect the Radiator hose. Squeeze the clamp to remove the hose. There will be coolant, be warned.
Next you will need to remove the 2 bolts from the thermostat housing.
You will new see the thermostat. make note of how the thermostat is installed so that your new one is installed the same. The thermostat will not work if installed upside down.
Clean the housing and the mating surfaces.
Now re-assemble your thermostat housing, and reconnect the rad hose.
Be sure to refill your coolant! You may need to fill your Rad, run the engine for a minute, then add more coolant to remove air pockets.