Step::1 Login to your Client Area.
Step::2 Once you logged in, click on Services and then My Services tab.
Step::3 Click on View Details button of your desired service.
Step::4 Now, click on Management Actions and select Upgrade/Downgrade option to place an upgrade/downgrade order.
Step::5 Click on Choose Product button of the service to which you want to upgrade/downgrade your existing plan.
Step::6 Kindly verify the differential amount, select the payment method and click on Click to Continue button.
That's It !
Go through the video tutorial to know the procedure in detail.You may check out the blog as well.