Hello irmajenkins4460. Below is instructions for remove devices using our xFi App.
You can remove a device that is not connected from the Devices section by selecting the name of the device either from the Devices section or from the profile where the device is assigned, then select Device Details > Forget Device. This will remove the device from the Devices section and unassign it from the profile it was associated with, if applicable. It will also permanently delete all historical network activity of this device. If the device reconnects to your home network, it will appear as a new device.
Learn more by visiting: https://www.xfinity.com/support/articles/personalize-customize-hnetwork-xfi
Please let me know if you need any further assistance.
@irmajenkins4460. You will have to disconnect each device manually via each devices 'WiFi settings' menu. If you are unable to do so, we recommend you reset your WiFi password. This will kick those devices on your network. Your only other option is to use the PAUSE feature instead of fully disconnecting them from your WiFi network.