cPanel (WHM): Installing on a Clean Server
First off, a caveat: for installing any control panel it’s recommended to use a clean server. Otherwise the server may break after the panel is installed.
If you have a clean server available, you can keep reading. If not - go find a clean server.
Recently WHM licenses started getting tied to server ip addresses. Before starting the install you need to make sure the needed license exists. You can use this page for that:
http://verify.cpanel.net/index.cgi
As a result you should get a picture like this:

Now connect to the server over ssh. You need superuser (root) rights to install WHM.
On the server go to the /home folder:
cd /home
Download the installer:
wget -N http://httpupdate.cpanel.net/latest
Run it:
sh latest
Follow the instructions.
Once the installation finishes, open the page with your server’s ip address in the browser:
https://your_server_ip:2087
Use the root username and password to log in.