For the latest version visit www.webmin.com and amend the shortcut in step 2 to the relevant version.
Get logged into your server via SSH and use the following 3 commands:
Step 1:
cd /usr/src
Step 2:
wget http://prdownloads.sourceforge.net/webadmin/webmin-1.470-1.noarch.rpm
Step 3:
rpm -i webmin-1.470-1.noarch.rpm
This will install Webmin to https://youripaddressordomain:10000