Ok are automatic and manual transfer case the same?
and do you have to remove transmission and to change any help will of great use

Yes, manual and auto tcases are the same.  You will need to replace it with a tcase from an 89-95 tcase though, because in 96 they changed the output shaft spline count.
It is easier to remove the tranny, in order to remove the tcase, IMO.  If you have a manual tranny, you have to take the tranny shifter tower off, because there is a hidden bolt underneath it, and the tcase won't come off, without it being removed.