How do you replace a water pump in a 2004 Buick rainier?

To replace the water pump in a 2004 Buick Rainier, first disconnect the negative battery cable and drain the coolant. Remove the serpentine belt and any components obstructing access to the water pump, such as the fan or engine cover. Unbolt the old water pump, clean the mounting surface, and install the new pump with a new gasket. Finally, reassemble all components, refill the coolant, and reconnect the battery.