how to remove upper front shock nut on 86 towncar

High i am restoring my towncar and replaced the rear shocks today.When I went to look at doing the front shocks I saw that the nut that holds the top nut on is in a kind of tight place how exactly you get if off? I don't see anyway to hold the threaded part and turn the nut at the same time.Am I missing something or is there a special too or technique I need to use?