Okay, the fan has the clutch unit on the front with the large nut attaching it to the water pump.Then 4 screws attach the pulley to the water pump as well.What is the best way to immobilize pulley/pump so l can get the fan blade clutch nut unscrewed?Ca not hold onto the fan or clutch unit since it simply spins.Ca not realy seem to hold onto the pulley either as it prefers to spin?Any suggested best ways?

can usually get 32mm wrench and hit it with hammer
in opposite direction Has backwards threads If not
get thick rag and real long big screwdriver and carefully
pry against pully so it doesnt turn and hit wrench with
hammer too loosen Or buy special bmw tools

First remember this tighten is loosen & loosen it tighten with the ''big nut'' on the fan clutch. And there is a tool u can buy (BMP design & Bavarian autosport have them) but l never bought one because l only could have used it once, & l try to keep my tool box as empty as l can.

All this with the belt on..Get the biggest screwdriver u have & a heavy hammer. Now put the screwdriver on the ''tighten'' side one of the flat sides edge. Take hammer & give it a big wack. As long as the last guy put the fan clutch on right it should take no more than 2 tries to loosen it. Once its loose just spin it off by the fan blades & pull it out. l only once had to use a sawsall (only time l could have used the tool)on both the water pump & fan clutch to do a water pump job & after inspection l found some moron used lock tight. When u reinstall just spin it on & that is it no need to tighten.. l like to put antiseize on the bolt threads so l know the next time l have to remove the fan it will come off like buttahr.