To opt out of a conversation/channel:

1. Tap on the “Messages” tab in the navigation bar at the bottom of your screen.
2. Locate the conversation you would like to leave and tap on the green power icon on the right side.
3. A confirmation box will pop up with the message “Are you sure you want to leave?.” Tap on the “Yes” button to confirm.
4. Once the power icon turns grey, that channel will be greyed out.
5. Here is how you can re-join a conversation and channel: How to join a channel/conversation.