Stand heating burner exchange

Hello, does someone have experience with replacing the burner with the Webasto ThermoTop C heater for diesel with the GP0 3.0 TDI? Webasto’s spare parts kit includes a water hose and various seals: Do I have to disconnect the connection of the heater to the cooling circuit to replace the burner? What is there to consider and how do I get to the heater? Thanks Moseltaler