How do you replace a water pump on a 2001 4runner?

To replace the water pump on a 2001 Toyota 4Runner, first, disconnect the negative battery terminal and drain the coolant. Remove the serpentine belt, then take off the timing belt (if applicable) to access the water pump. Unbolt the old water pump, clean the mating surfaces, and install the new pump with a new gasket. Finally, reassemble everything, refill the coolant, and run the engine to check for leaks.