Not hard to replace, and reasonably priced. Please replace the short hose down there, as it is pretty much inaccessable with the water pump in place. A genuine MB water pump will have a small MB star logo on it. I would not use anything but a genuine MB water pump.
2004 C240 Wagon 203.261 Baby Benz
2008 ML320 CDI Highway Cruiser
2006 Toyota Prius, Saving the Planet @ 48 mpg
2000 F-150, Destroying the Planet @ 20 mpg
And remember folks, Only You Can Prevent Hilliary.