How do you replace a thermostat for an 1985 Ford Tempo?

To replace the thermostat in a 1985 Ford Tempo, start by ensuring the engine is cool and disconnect the negative battery cable. Drain the coolant from the radiator, then locate the thermostat housing, which is typically at the end of the upper radiator hose. Remove the housing bolts, take out the old thermostat, and clean the mating surfaces. Install the new thermostat with the correct orientation, reattach the housing, refill the coolant, and reconnect the battery.