If you follow the instructions given by Zubair you get to a page titled "Hosting Account Management". About half way down this page you should see two buttons - Login to cPanel and Login to Webmail. If you click on the button that says "Login to cPanel" your cPanel should open up, at which point you can continue following Zubair's directions.
If you do not see the cPanel button at this location there may be a temporary problem related to the server upgrades in which case you should try again in a few hours.