[SOLVED] How To Remove A Desktop

I have recently done a clean install of F18 including the MATE desktop which, as a fairly basic user, I find quite easy to use - I DID NOT install the gnome desktop.
Initially I installed the LXDE desktop.

I then installed the MATE and CINNAMON desktops via the following commands :
yum groupinstall "MATE Desktop"
yum groupinstall "Cinnamon Desktop"

I really like the MATE desktop and so I thought I would remove Cinnamon which I no longer need.

I tried the following command
yum groupremove "Cinnamon Desktop"
but when I did that yum listed out a plethora of packages and dependencies to be erased - seemingly everything that is installed.

It ended without removing anything with the last few details shown below :

---> Package mythes-en.noarch 0:3.0-11.fc18 will be erased
--> Processing Dependency: /sbin/new-kernel-pkg for package: kernel-PAE-3.8.11-200.fc18.i686
Skipping the running kernel: kernel-PAE-3.8.11-200.fc18.i686
--> Processing Dependency: /bin/sh for package: kernel-PAE-3.8.11-200.fc18.i686
Skipping the running kernel: kernel-PAE-3.8.11-200.fc18.i686
--> Restarting Dependency Resolution with new changes.
--> Running transaction check
--> Finished Dependency Resolution
Error: Trying to remove "systemd", which is protected
Error: Trying to remove "yum", which is protected

I was wondering why it would list so much to be removed and how, if it is possible, I can delete just Cinnamon