If you need to upgrade your hosting package because you need more resources, or if you need to downgrade because you need less resources, this can be done in your client area.
Once you have logged into your client area, click on Services > My Services in the top menu:
All your Services will then be listed.
Click on the green Active button next to the correct hosting Service:
The Actions menu on the left will have an Upgrade/Downgrade link. Click on it.
All the available Upgrade and Downgrade options - all the hosting Services you are allowed to switch to from your current hosting Service - will be displayed on the page.
Select the billing cycle you would like to use from the drop-down selector next to the correct hosting Service, and then click on the blue Choose Product button.
Complete your Upgrade/Downgrade order.