The shaft should rotate freely and normally should be easy to remove.
This post is a good one to remind us all that the lower shaft of the rear uprights should be modified so it can be greased and serviced regularly.
After you get the shaft out ... do not forget to replace the inner bearing sleaves (part #16 on the earlier posted drawing). They have a teflon coating on the inner face. I also think some of the washers have a teflon coating on their face (Part #15). In any case ... I replaced all the end washers as well when I installed my modified lower shaft kit.
I did this back in 1992. Haven't had a problem since. Check out
http://www.panteraplace.com/page87.htm - it seems to cover it well.
HTH
B.G.