How do you replace thermostat on 2002 Infiniti I35?

To replace the thermostat on a 2002 Infiniti I35, first, ensure the engine is cool and disconnect the negative battery cable. Drain the coolant from the radiator, then remove the upper radiator hose and the thermostat housing, which is typically secured by bolts. Replace the old thermostat with a new one, ensuring the gasket is in place, and reassemble the housing and hose. Finally, refill the cooling system with coolant and reconnect the battery.