The binding may have gone away when the pully is installed. That was the case a few years ago when I worked on alternators frequently.
The easiest way to remove the pulley is with a 1/2" impact wrench, like the one used to remove wheels. Hold the pully and alternator with a rag or leather gloves and spin the retaining nut off with the impact wrench. It comes off very easy that way. Make sure to transfer not only the pulley and nut, but also the spacer that goes on before the pulley and also the lock washer that goes between the pulley and the nut. Often the parts guy at a Ford dealership will help you get the pulley transferred. I did a lot of them at no charge for parts customers.
