OK, assuming you have A/c and Power Steering. and that you have a 2.0 DOHC.
the Thermostat and the Housing are a complete unit, there are two models one with a sensor one without. There is no way to "see" witch until you remove it, because its very tight in there. so here we go.
I did this procedure in about 3 hours taking my time. hope this helps.
Chilibean
The thermostat housing on a 2008 cobalt where the lower radiator hose connects to the radiator.
http://jimwarholic.com/jotspot/2008/01/honda-accord-cabin-filter-replacement.php
To change the thermostat in a 2008 Jeep Compass, first ensure the engine is cool and disconnect the negative battery terminal. Drain the coolant and remove the upper radiator hose connected to the thermostat housing. Unbolt the thermostat housing, replace the old thermostat with a new one (ensuring the gasket is in place), then reassemble everything in the reverse order. Finally, refill the coolant and check for leaks before reconnecting the battery.
According to the 2008 Ford Focus Owner Guide : With engine oil filter change : ( 4.5 U.S. quarts / 4.3 litres of 5W-20 )
Changing a thermostat on a 2008 Dodge Avenger can be difficult because there area two thermostats. One is located under the intake manifold inside a housing unit, and the second is at the end of the radiator hose.
A 2008 Focus.
According to the 2008 Ford Focus Owner Guide : With engine oil filter change : The 2.0 litre four cylinder engines take ( 4.5 U.S. quarts )
The 2008 Ford Focus has 16 valves.
The 2008 Ford Focus is a gas-powered vehicle.
The 2008 Ford Focus has a 5-speed manual.
The 2008 Ford Focus has an inline 4 engine.
The engine thermostat, on a 2008 Chevy Impala 3.5 V6, is located on the lower front side of the engine. The thermostat will have a water hose going into the top of it.