1990 PS pulley removal issuse

[alanstoy]

Hi,
Ok, I have a 90 Tbird 3.8 coupe, not supercharged with A\C
I am replacing the water pump, and am in the middle of pulling everything.
How do i remove the ps pump pulley, so i can remove the ps pump bracket?
The pulley has a hex like nut in the middle of it, so i cant see just using a puller on it. and the hex nut is on very tight, cant seem to hold the pulley from spinning as i try.
Any hints or trick to this?
Thanks for any help.
Alan