Open a web browser and type one of the following URL's into the address bar: http://www.yoursite.com/cpanel or http://www.yoursite.com:2082
A good security practice would be to type https://www.yoursite.com/cpanel or https://www.yoursite.com:2082 into web browser's address bar if the website has a SSL certificate.
A popup window will appear prompting for a User Name and Password.
Type the Account Username into the User Name textbox.
Type the Account Password into the Password textbox.
When the credentials have been verified the web browser will be redirected to the cPanel Main Page.
Troubleshoot
Due to strict Internet Service Provider's (ISP) restrictions you may not be able to access cPanel Control Panel which uses port 2082.