Step 1 » Create a new file webmin.repo in /etc/yum.d/ and add the below code.

[Webmin]
name=Webmin Distribution Neutral
#baseurl=http://download.webmin.com/download/yum
mirrorlist=http://download.webmin.com/download/yum/mirrorlist
enabled=1

Step 2 » Install webmin GPG key using below command.

rpm --import http://www.webmin.com/jcameron-key.asc

Step 3 » Update the repositories.

yum check-update

Step 4 » Now install webmin package using yum .

yum install webmin

Step 5 » Start the service and make it start automatically.

chkconfig webmin on
service webmin start

Step 6 » By default, Webmin will listen on port 10000, Allow this port in iptables if it is enabled.

iptables -I INPUT -p tcp --dport 10000 -j ACCEPT
service iptables save

Step 7 » Now open http://serverip:10000 in your browser, you could see the below screen after login ( Use root username and password ).