If you created a Sling TV account through your Amazon device, you can change your subscription in app. Follow the steps below to make changes to your subscription.
First scroll to the right on your menu and choose Settings. Then visit your Account.
Here you can change your service by clicking Add/Remove Service.
After clicking Add/Remove Service you can change to the Sling Orange base service, the Sling Blue base service, or select both Sling Orange and Sling Blue base services.
By choosing a different service, any extras will initially be removed.
Once you choose one or more base services you will be able to pick any extras you would like to add to your base service(s).
Next, you will see an updated review of your service. Be sure to review your order before pressing FINISH & SUBMIT.
For each service you purchased, click Subscribe to confirm your subscription changes.
If you are still having issues with changing your subscription, please make sure the device you are using is registered with the Amazon account with which you created your Sling account