In removing the cooling fan on an E34 1995 525i M52 Engine, how do you keep the water pump pulley from turning? Bentley manual says:

Place a 32mm wrench on fan clutch nut. Strike wrench quickly in a clockwise direction (working from the front of car) to loosen nut.

This is not working for me.

Bentley manual continues:

If the nut is difficult to loosen, use a tool to hold the coolant pump pulley stationary. BMW has a special tool for this purpose (..tool no. 11 5 050..)

How does this tool work and can I get it anywhere else other than BMW? Are they any other tricks to removing the fan?

Thanks

Eric Fraser