How do you change a heater core on a 2002 Toyota Tundra?

To change the heater core on a 2002 Toyota Tundra, start by disconnecting the battery and draining the coolant from the radiator. Remove the dashboard and the center console to access the heater core housing, which involves detaching various components and screws. Once the housing is open, remove the old heater core and replace it with the new one, then reassemble everything in reverse order, ensuring all connections are secure. Finally, refill the coolant and check for leaks before reconnecting the battery.