As rusty as they look, I would use some heat on them. It is really easy to break a stud off and then you have to pull the hub. The stud is only 3/4" and breaks easily The inner and outer nuts are available at any large truck dealership and they are cheap. This is the inner right. Left ends in L
http://www.ryderfleetproducts.com/euclid-e7895r/inner-nut-p-439-e7895r

This is the right outer nut.

http://www.ryderfleetproducts.com/euclid-e5652r/single-cap-nut-p-439-e5652r