Mercedes W221 S550 (2006-20013) 4-Way Heater Control Valve Coolant Leak Replacement

Easier way to replace the 4-way heater control valve. No need to open the hood to full upright position, no need to remove the wiper blades and no need to remove the window cowl.
Note that the rubber spacer wheel that I referred to is used to make sure the control valve does not rest on adjacent piping that gets hot and may degrade the control valve.