need to take off water pump how do you take off the fan that right before pulley

You need a fan clutch wrench. you have to hold the pulley and turn the fan with the wrench. Some auto part stores rent the wrench set.

The large NUT!... well you turn it the same direction the fan normally turns in.. Usually a direct blow, applied sharply in the correct direction will do the trick but you must make sure you don't hit anything else in the process.. A little tricky