Login as the root user to SSH and run the following commands to install CSF:
# wget http://www.configserver.com/free/csf.tgz # tar -xzf csf.tgz # cd csf # sh install.sh
If you would like to disable APF+BFD (which you will need to do to avoid conflicts):
# sh disable_apf_bfd.sh
Now, you can then configure csf and lfd in WHM, or edit the files directly in /etc/csf/*