How do you replace thermostat in rover 75?

To replace the thermostat in a Rover 75, first, ensure the engine is cool and disconnect the battery. Remove the engine cover and locate the thermostat housing, typically situated near the engine block. Drain the coolant, then unbolt and remove the thermostat housing to access the thermostat. Replace the old thermostat with a new one, reassemble the housing, refill the coolant, and reconnect the battery.