How do you replace interior radiator on citreon xsara?

To replace the interior radiator on a Citroën Xsara, first, disconnect the battery and drain the coolant. Remove the dashboard and any components blocking access to the heater matrix, then disconnect the hoses leading to the radiator. Carefully remove the old radiator and install the new one, reconnecting the hoses and reassembling the dashboard. Finally, refill the coolant system, bleed any air, and reconnect the battery.