FL - try searching the arhives on this list.
Key in "FLX" in the search field. When I did this, 3 formers posts came up, The first was titled "300E Waterpump" by Benzmac. At the very bottom, Benzmac gives some pointers on expediting M103 H2O pump removal. The Snap-On tool/part number is also mentioned. Good luck.

Mike Murrell
Boerne Texas
'91 300-SEL