I'm trying to change the water pump on my 6.0 diesel (2003). How do you get the fan assembly off? Thanks

Sorry if this is to late, Maybe it will help others. After you remove the front shroud You need a hammer and a long punch or a steel rod. Hit the nut a few times and it will break loose and you will be able to spin it off with the fan blades. I have personally done this on three different 6.0 diesels 06 models.