the only way i know of too switch between the to is to reinstall things over/ on top of others
installing the nvidia.run driver overwrites fedoras mesa install
then reinstalling mesa overwrites nvidia's opengl
i do something like this whenever i reinstall my driver ( see sig)
i install the .run then run " yum reinstall mesa* " ( that reinstalls mesa-libGl,mesa-libGl-devel ,mesa-libGLU ,mesa-libGLU-devel , mesa-libGLw , mesa-libGLw-devel )
OpenSUSE 13.2-64bit & Scientific Linux 6.6-64bit ( fedora 4 to 11) and 20 on KVM
My Celestia Downloads
h t t p ://celestiamotherlode.net/catalog/show_creator_details.php?creator_id=10