How to remove the heater pipe joint behind Citroen C 5?

The disassembly method of Citroen C 5 rear heater hose connector is as follows:

Removal and installation of heating device:

(1) Drain the coolant from the cooling system.

(2) Remove the control panel.

(3) Separate the cable fixing piece on the left side of the heater and remove the screw on the terminal.

(4) Pull out the wire connector behind the blower motor.

(5) Disconnect the vacuum tube and lighting line behind the heater control device.