In cPanel servers:
cd /etc/csf sh uninstall.sh
In DirectAdmin servers:
cd /etc/csf sh uninstall.directadmin.sh
In No-Panel Linux servers:
cd /etc/csf sh uninstall.sh
cd /etc/csf sh uninstall.sh
cd /etc/csf sh uninstall.directadmin.sh
cd /etc/csf sh uninstall.sh