If you are subscribed to Grokker through Comcast Xfinity it is managed completely by Comcast. Therefore, you must cancel your membership through Comcast.
- Go to Xfinity.com and log into your account.
- You can upgrade or change your service by clicking 'Manage Plan'.
- To add or change your premium channels click 'Manage Channels'.
- Or you can do this by calling Comcast at 1-800-XFINITY (1-800-934-6489) and follow the prompts to "cancel service" or "downgrade service."