The fan clutch has left handed threads... Right to loosen and left to tighten.... Ford repair manual instructions below...
Remove the fan shroud as outlined in Removal and Installation,Radiator in this section.
CAUTION: On 3.0L engines only, the large nut which attaches fan clutch to the hub of the water pump shaft has a left-hand thread and must be rotated clockwise for removal.
Remove the nut using Fan Clutch Holding Tool T84T-6312-C and Fan Clutch Nut Wrench T84T-6312-D.
Remove the fan and fan clutch as an assembly.
Remove the bolts attaching the fan to the fan clutch, if necessary.
CAUTION: On 3.0L engines only, the fan clutch nut has a left-hand thread and must be rotated counterclockwise for tightening.
For installation, follow removal steps in reverse order. Tighten the fan-to-clutch bolts to 6-8 Nm (53-71 lb-in). Tighten the fan clutch assembly nut to 47-63 Nm (34-46 lb-ft).
I have seen Technician use air chisels to remove the fan clutch. Even a large wrench and hammer with channel locks holding the pulley.. Call around some Parts store rent tools especially specialty tools.. Check your local dealer they might be nice enough to loan them to you. If you leave a deposit on the tools.. They do cost money to replace if lost or stolen...