I know where the thermostat is but do I need to take the housing
surrounding the thermostat apart or just unscrew the thermostat out?

 

there is a housing around the thermostat that has two bolts that you will need to take off in order to get to it, after that is off make sure that the old seal comes completly out, then put the new one in and tighten it all back up. o ya dont forget to drain your radiator and bleed the system to make sure for no air bubbles when you put water back in!