When the heating box is removed, it is necessary to drain the coolant in the cooling system. Remove the air conditioning control panel, separate the cable holder on the left side of the hot air equipment, remove the screw of the terminal, and then unplug the terminal behind the blower motor. Then disconnect the vacuum tube and the lighting line behind the heater control. Put a container under the engine, put the heater water supply pipe behind the cylinder head, and finally remove the heater water supply pipe behind the cylinder head.