Thread: Viscous coupling fan removal

I've decided to replace the viscous coupling fan on my 84 rangie. I have the fan with nut in the centre that has to be removed to get the fan and coupling off. Is the thread right hand or left hand, and how do you stop the adaptor thats attached to the pulley from turning when your trying to undo the nut. I would appreciate any help on these questions. The job looked simple, move cowling out of the way, undo nut, remove fan with viscous coupling , replace and reverse of process. Thanks

LH thread
belt tight
Big spanner
belt with hammer , towards passenger side.
Regards Philip A