To activate the EPEL repository, run the following command as root:

rpm –import http://download.fedora.redhat.com/pub/epel/RPM-GPG-KEY-EPEL

rpm -Uvh http://download.fedora.redhat.com/pub/epel/5/i386/epel-release-5-3.noarch.rpm

After successful execution, there will be two new files in your yum configuration directory, /etc/yum.repos.d/.

epel.repo
epel-testing.repo

The epel-testing is disabled by default.

References:

• http://wiki.rivalug.org/index.php/Centos5
• http://fedoraproject.org/wiki/EPEL