Yes you will need probably 3-4L of coolant and some distilled water if you drain the intercooler loop and throw the old fluid away. Only use mercedes coolant. The pump is also called auxillary pump on many sites.
Yes that is it with fluid. Here is the pump on its own too
https://www.fcpeuro.com/products/mer...ump-0392022010

 

You can also clamp the coolant arrival pipe, that's what I did when changing my pump on my SL. You then loose only the collant in the pump itself.

And remember: Do this operation with a cold engine !!!