We have already discusses about how to install ubuntu 16.04 LAMP server
Now you need to install webmin from APT repository
sudo sh -c ‘echo "deb http://download.webmin.com/download/repository sarge contrib" > /etc/apt/sources.list.d/webmin.list'
wget -qO -- http://www.webmin.com/jcameron-key.asc | sudo apt-key add --
sudo apt-get update
sudo apt-get install webmin
Now you need to go to https://serverip:10000
Ubuntu in particular don't allow logins by the root user by default. However, the user created at system installation time can use sudo to switch to root. Webmin will allow any user who has this sudo capability to login with full root privileges.
Once you logged in you should see similar to the following screen