wget http://webmin.com/download/deb/webmin-current.deb
then type ls which will display the downloaded webmin(webmin-current.deb)
dpkg -i webmin-current.deb
it will install (or) will list missing dependencies then type.
apt-get -f install
This command will fix(-f) the missing dependencies and install webmin
On successfull installation of webmin it will display
Webmin install complete. You can now login to https://ubuntu:10000/ as root with your root password, or as any user who can use sudo
to run commands as root.
open the link https://ubuntu:10000/
It will ask for username and password. Enter as root user.