1. Drain the engine coolant. (See ENGINE COOLANT REPLACEMENT [AJ (3.0L Duratec)].) (See ENGINE COOLANT REPLACEMENT [L3].) (See ENGINE COOLANT REPLACEMENT [YF (2.0L Zetec)].)
2. Disconnect the heater hoses from the heater core.
3. Remove the dashboard. (See DASHBOARD REMOVAL/INSTALLATION.)
4. If equipped with A/C, remove the cooling unit. (See COOLING UNIT REMOVAL/INSTALLATION.)
5. Remove the heater unit.
6. Install in the reverse order of removal.