EPEL extension is extra packages for enterprise Linux, its helps and provides to creates, maintains, manages additional packages for enterprise Linux like,  CentOS, RHEL, Scientific Linux, Oracle Linux.

You want to be enable REPL repository in your system and we can Installing this package using yum command,

Check your Linux Version:

# cat /etc/redhat-release
CentOS Linux release 7.0.1406 (Core)

Download package and Install:

 RHEL/CentOS 7 64-Bit 

 
# wget http://dl.fedoraproject.org/pub/epel/7/x86_64/e/epel-release-7-5.noarch.rpm
or
# wget http://ftp.riken.jp/Linux/fedora/epel/7/x86_64/e/epel-release-7-5.noarch.rpm

For example install rpm package, Once you have downloaded the packages just install it
 
 # rpm -ivh epel-release-7-5.noarch.rpm

Preparing...           ################################# [100%]
Updating / installing...
   1:epel-release-7-5   ################################# [100%]

If you want to remove the repo rpm package, First find the package name and remove it
# rpm -qa | grep epel-release
epel-release-7-5.noarch
# rpm -e epel-release-7-5.noarch

RHEL/CentOS 6 32 Bit
 
# wget http://ftp.riken.jp/Linux/fedora/epel/6/i386/epel-release-6-8.noarch.rpm
or
# wget http://ftp.jaist.ac.jp/pub/Linux/Fedora/epel/6/i386/epel-release-6-8.noarch.rpm

 
RHEL/CentOS 6 64-Bit 
 
​# wget http://ftp.riken.jp/Linux/fedora/epel/6/x86_64/epel-release-6-8.noarch.rpm
or
# wget http://dl.fedoraproject.org/pub/epel/6/x86_64/epel-release-6-8.noarch.rpm

RHEL/CentOS 5 32-Bit
 
​# wget http://ftp.riken.jp/Linux/fedora/epel/5/i386/epel-release-5-4.noarch.rpm
or
# http://mirrors.123host.vn/epel/5/i386/epel-release-5-4.noarch.rpm

RHEL/CentOS 5 64-Bit
 
​# wget http://ftp.riken.jp/Linux/fedora/epel/5/x86_64/epel-release-5-4.noarch.rpm
or
# wget http://dl.fedoraproject.org/pub/epel/5/x86_64/epel-release-5-4.noarch.rpm