First of all download the raw .so file from zend:
Copy the one relevant to your PHPversion to /usr/lib64/php/modules/
eg.:cp ioncube_loader_lin_5.3.so /usr/lib64/php/modules/
Then in your /etc/php.d/ directory create the file:
vi /etc/php.d/zend.ini
zend_extension = /usr/lib64/php/modules/ioncube_loader_lin_5.3.so
After that restart apache/httpd and you'll be good to go!........