How do you replace the thermostat located on a 1987 Toyota Corolla?

To replace the thermostat on a 1987 Toyota Corolla, first, ensure the engine is cool and disconnect the negative battery cable. Drain the coolant by removing the lower radiator hose or the drain plug. Next, remove the thermostat housing bolts, take out the old thermostat, and clean the mating surfaces. Install the new thermostat with the spring side facing the engine, reassemble the housing, and refill the coolant before reconnecting the battery.