How to replace thermostat on 2006 Dodge Ram 1500

Do I need to purchase the felpro housing gasket as well as the thermostat? The new Tstat comes with its own seal, and the auto parts guys don't stock the housing gasket. This tells me that the metal flange/housing that the radiator hose connects to is the only thing to remove and this does not require a gasket since the tstat has its own seal/ Is this correct?

Asked by for the 2006 Dodge Ram 1500
There is a rubber seal which surrounds the outer portion of the thermostat. This is what seals the thermostat housing. You do not need an additional gasket.
How about draining coolant beforehand? Any mystery to it?