How do you replace the thermostat on 2003 mini cooper?

To replace the thermostat on a 2003 Mini Cooper, first, ensure the engine is cool, then disconnect the negative battery terminal. Remove the air intake duct, then locate the thermostat housing, which is typically near the engine block. Disconnect the coolant hoses and remove the bolts holding the thermostat housing in place. Replace the old thermostat with a new one, reassemble the housing, reconnect the hoses, and refill the coolant before reconnecting the battery.