Remove armrest

Anyone tried this on Windstar? I'm talking the inside (right) armrest on the drivers side. The vinyl has cracked on the armrest itself and the base of the chair....I'd like to put on a seat cover (which is hindered by the armrest itself) and swap the armrest out to a seat in the middle where it will probably be unused.

I've noticed that the armrest cover seems to have stitching around but its doesnt seem to be zippered..so its not coming off. There is a pretty heft nut/blot combo that I can't seem to budge...but maybe thats what has to?