Firstly you will need to Login
On your Dashboard once loged in select services button:
1. From your Home sceen after you have loged in to billing, look at the top buttons and see:
Services button, click it.
2. Now your services will be listed and to the right you'll see a Manage Product Button, click the button to edit your service.
3. To the left, under actions you'll see an upgrade button do click on that to enter upgrade options.