Import the key

[root@ambush ~]# rpm --import http://ftp.riken.jp/Linux/fedora/epel/RPM-GPG-KEY-EPEL-6

Download the Epel package and install it

[root@ambush ~]# wget http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm
[root@ambush ~]# rpm -ivh epel-release-6-8.noarch.rpm 
Preparing...                ########################################### [100%]
   1:epel-release           ########################################### [100%]
[root@ambush ~]#

Now you can install packages from the EPEL repository.