Installation is quite straightforward:
Login as the root user to SSH and run the following commands.
rm -fv csf.tgz
tar -xzf csf.tgz
If you would like to disable APF+BFD (which you will need to do if you have
them installed otherwise they will conflict horribly):
That's it. You can then configure csf and lfd in WHM, or edit the files
directly in /etc/csf/*