D20.20-1007-01
1 Use e.g. water pump pliers to press in cam (arrow) at front and rear and separate plug connection of coolant flow line for heater.
D20.20-1008-01
2 Detach coolant return flow line for heater at coolant pipe.
3 Install in the reverse order.
Inspect condition of coolant lines and hose clamps, replace if necessary.