Boy Steve, I have no experience on replacing them. I wouls suggest you give your friendly neighborhood Ford parts guy and ask him He will be able to tell you if the part is available seperately and even could provide you with an exploded wiew of the hinge assembly. Somehow I doubt that you can get just the one part and replacing a hinge can be kind of tricky because of the door alignment. if you get it wrong you can screw up the paint on your car in several places or you will end up with noise and so on.
You could also maybe check with body shops and see what they would charge you to R&R the hinge assembly.
I wouldn't go used. No since buying something that's already wearing out. Bruised shins are a terrible thing.
Good Luck! Keep us posted on what you find out!
Kate