How do you replace heater core 2002 Ford E-150 van?

To replace the heater core in a 2002 Ford E-150 van, first, disconnect the battery and drain the coolant from the radiator. Remove the dashboard and the center console to access the heater core, which is located behind the firewall. Disconnect the hoses and mounting bolts securing the heater core, then replace it with the new unit and reassemble everything in reverse order. Finally, refill the coolant, bleed the system, and reconnect the battery.