How do you change the water pump on the BMW M47 engine fitted to the rover 75?

To change the water pump on a BMW M47 engine in a Rover 75, first ensure the engine is cool and disconnect the battery. Drain the coolant and remove the drive belts, followed by the timing belt if necessary. Unbolt the water pump from the engine block, clean the mating surfaces, and install the new pump with a new gasket. Finally, reassemble all components, refill the coolant, and check for leaks.