Removing KDE from Fedora21, groupremove not working

I am trying to remove KDE from my Fedora 21 installation in favor of XFCE. I have tried a few different commands and neither of them work.

#yum groupremove "KDE Plasma Workspaces"

and also

#yum  groupremove  kde-desktop-environment  --exclude=fedora-release\*

Both fail to find the kde group and remove it. I think it has something to do with the fact that I upgraded from fedora20 with fedup and used the non-product selection.