How do you change thermostat on 1993 Mazda rx7?

To change the thermostat on a 1993 Mazda RX-7, first, ensure the engine is cool and disconnect the negative battery terminal. Drain the coolant from the radiator, then remove the hoses connected to the thermostat housing. Unbolt the thermostat housing, replace the old thermostat with a new one (ensuring the spring side faces the engine), and reassemble everything in the reverse order. Finally, refill the cooling system with coolant and check for leaks.