Buy the required license from red hat
( $49 to $299 for the desktop and $349 to over $6,499 for the server )
https://www.redhat.com/apps/store/desktop/
https://www.redhat.com/wapps/store/catalog.html
and RHEL 5 is starting to show it's age
5.8 is the current in the older 5 series and 6.3 is the current
OR
install one of the FREE rebuilds
CentOS 5.8 or 6.3
and
ScientificLinux 5.8 and 6.3