How do you change thermostat in 2007 grand prix?

To change the thermostat in a 2007 Pontiac Grand Prix, first ensure the engine is cool and disconnect the negative battery cable. Drain the coolant from the radiator, then remove the upper radiator hose connected to the thermostat housing. Unbolt the thermostat housing, remove the old thermostat, and clean the mating surfaces before installing the new thermostat with a new gasket. Finally, reassemble everything, refill the coolant, and reconnect the battery.