Re: How do I install kde4 and remove xfce4?
I'd actualy make it the other way round, first remove XFCE, and immediatly install KDE.
That is, because yum will probably remove some packages you would need, and the install after removal might install them again.
Fedora Manual: http://docs.fedoraproject.org
sudo st tweak repo toggle fedora-rawhide ; st iso dl-fed -respin && st iso usb