Go to Zendguard download page. You will have to create an account then download the appropriate version to your desktop, untar, then copy ZendGuardLoader.so to /usr/lib/php/modules for 32bit and /usr/lib64/php/modules for 64bit.
Create file to enable zendguard in php. Replace 'lib' with 'lib64' for 64bit
nano /etc/php.d/zendguard.ini
zend_extension=/usr/lib/php/modules/ZendGuardLoader.so
zend_loader.enable=1
zend_loader.disable_licensing=0
zend_loader.obfuscation_level_support=0
Install EPEL Repo
rpm -Uvh http://download.fedoraproject.org/pub/epel/6/i386/epel-release-6-8.noarch.rpm
Install commercial module dependencies.
yum install incron prosody