deactivate leased modem

Concern moved here to the Customer Service help section for greater exposure to Comcast corporate employees (The Digital Care Team) for assistance.

Hi there, @user_90j8vk! Congratulations on your new modem! We want things to be at your fingertips so you are able to add and activate your new modem using the Xfinity app. Here are the instructions, https://www.xfinity.com/support/articles/activate-xfi-gateway-app. Please let us know if you have any concerns as you go through the process. We are happy to assist you. 

After you have the new modem activated, you can return the Xfinity modem to have it removed from your account. This link shows how to return Xfinity equipment, https://www.xfinity.com/support/articles/returning-your-equipment.