Playing with desktop environments and then you want to remove them

# narrow down the group list to the ones you are interested in
yum grouplist | grep -Ei '(xfce|kde)'

# then get the packages you need to remove
yum group info Xfce

# then try and get a list of the packages in that group formatted as a flat list
yum group info Xfce | grep -v : | grep -v "Setting up" | tr \\n ' ' | sed -r 's/\s{1,}/ /g'

 Thunar desktop-backgrounds-compat xfce-utils xfce4-panel xfce4-session xfce4-settings xfconf xfdesktop xfwm4 NetworkManager-gnome Terminal abrt-desktop gdm gtk-xfce-engine leafpad openssh-askpass orage polkit-gnome thunar-archive-plugin thunar-volman tumbler xarchiver xfce4-appfinder xfce4-icon-theme xfce4-mixer xfce4-power-manager xfce4-session-engines xfwm4-theme-nodoka parole ristretto thunar-media-tags-plugin thunar-vcs-plugin xfbib xfburn xfce4-battery-plugin xfce4-cellmodem-plugin xfce4-clipman-plugin xfce4-cpugraph-plugin xfce4-datetime-plugin xfce4-dict xfce4-dict-plugin xfce4-diskperf-plugin xfce4-eyes-plugin xfce4-fsguard-plugin xfce4-genmon-plugin xfce4-mailwatch-plugin xfce4-mount-plugin xfce4-mpc-plugin xfce4-netload-plugin xfce4-notes-plugin xfce4-notifyd xfce4-places-plugin xfce4-quicklauncher-plugin xfce4-radio-plugin xfce4-screenshooter xfce4-screenshooter-plugin xfce4-sensors-plugin xfce4-smartbookmark-plugin xfce4-stopwatch-plugin xfce4-systemload-plugin xfce4-taskmanager xfce4-time-out-plugin xfce4-timer-plugin xfce4-verve-plugin xfce4-volumed xfce4-wavelan-plugin xfce4-weather-plugin xfce4-websearch-plugin xfce4-xfapplet-plugin xfce4-xfswitch-plugin xfce4-xkb-plugin xfmpc xfwm4-themes imsettings-xfce pinentry-gtk 

# close your eyes and cringe while using the flat list to remove the group
yum remove Thunar desktop-backgrounds-compat xfce-utils xfce4-panel xfce4-session xfce4-settings xfconf xfdesktop xfwm4 NetworkManager-gnome Terminal abrt-desktop gdm gtk-xfce-engine leafpad openssh-askpass orage polkit-gnome thunar-archive-plugin thunar-volman tumbler xarchiver xfce4-appfinder xfce4-icon-theme xfce4-mixer xfce4-power-manager xfce4-session-engines xfwm4-theme-nodoka parole ristretto thunar-media-tags-plugin thunar-vcs-plugin xfbib xfburn xfce4-battery-plugin xfce4-cellmodem-plugin xfce4-clipman-plugin xfce4-cpugraph-plugin xfce4-datetime-plugin xfce4-dict xfce4-dict-plugin xfce4-diskperf-plugin xfce4-eyes-plugin xfce4-fsguard-plugin xfce4-genmon-plugin xfce4-mailwatch-plugin xfce4-mount-plugin xfce4-mpc-plugin xfce4-netload-plugin xfce4-notes-plugin xfce4-notifyd xfce4-places-plugin xfce4-quicklauncher-plugin xfce4-radio-plugin xfce4-screenshooter xfce4-screenshooter-plugin xfce4-sensors-plugin xfce4-smartbookmark-plugin xfce4-stopwatch-plugin xfce4-systemload-plugin xfce4-taskmanager xfce4-time-out-plugin xfce4-timer-plugin xfce4-verve-plugin xfce4-volumed xfce4-wavelan-plugin xfce4-weather-plugin xfce4-websearch-plugin xfce4-xfapplet-plugin xfce4-xfswitch-plugin xfce4-xkb-plugin xfmpc xfwm4-themes imsettings-xfce pinentry-gtk 

# finally make sure you run the command to install the one you want to use so it will install anything missing
yum groupinstall "GNOME Desktop Environment"

Removing a Desktop Environment once you have finished playing with it. Fedora