You can do this by following these few steps:
1. Log in to our billing panel
2. Click on services  then click on the service you want to upgrade/downgrade
3. Click on "Actions" on the left column then on "Upgrade/downgrade configurable options
4. Upgrade/Downgrade to the desired options and choose to Continue
5. You will be taken to the invoice for the cost to upgrade for the remainder of the current period.
6. Pay - once paid your service will automatically be upgraded/downgraded.

If you downgrade your server the price difference will be credited to your roxservers.com balance so you can use it to pay your next invoice.

If however there has already be generated a new Invoice for the Upcoming month, you will have to
pay that invoice first and then do the Upgrade / Downgrade. Note that if you are downgrading you will get refunded a part of your payment on your roxservers.com balance so you do not lose anything.

Please note that if you add/remove a voice server or change the voice server type it will require manual intervention. Please submit a support ticket after validating your upgrade/downgrade request in this case.