Not having one in front of me, I will tell you how to do it for 80s/mid 90s.
Usually the nut is too rusted in place and the only way is to loosen the parking brake assembly.
If yours can be freed up, hold the cable with a 5/16 wrench while undoing the nut. My experience is you can never get enough slack to totally remove the cable. Get as much slack as you can, take the parking brake off as much as you can, twist it to the side, pull on the cable end with a needle nose vise grip, and pull the ferrule out enough to clear the swinging bracket end.
Now, if you can, you might be able to remove the cable itself from the bracket. They sell a special tool to hold the crimps down, but, this method works too. Get a small clamp, put it over the cable and squish down the fingers, slide it through the hole enough so the fingers clear, loosen the clamp enough that it will slide as you push the rest of the cable through.
You do NOT want to remove the cable itself from the floor, you will most likely mess up the rubber seals and such. You should be able to get enough slack by pushing the cable housing into the truck, to help remove the inner core from the parking brake bracket.
Thanks for the response. I just had this emergency brake assembly replaced less then a year ago...this one failed within that year..out of warranty with the dealership. So I am ordering the OEM part myself and doing it. All the parts and hardware are pretty new, so it shouldnt be rusted. Thanks again