How do you replace radiator heater in opel corsa?

To replace the radiator heater in an Opel Corsa, first, ensure the engine is cool and disconnect the battery. Drain the coolant from the system, then remove the dashboard and any necessary components to access the heater core. Disconnect the hoses from the heater core, unbolt it from its housing, and replace it with the new heater core. Reassemble everything, refill the coolant, and check for leaks before reconnecting the battery.