If you've gone live by mistake, you can simply reset a session without having to create a new one.
If you've come across a scenario where you need a do-over in the same event, you can reset the session.
Once you have ended the broadcast, you can click on "Options" from the top right.
Then from the drop-down menu select "Reset session."
You'll then be prompted to confirm. Keep in mind that once you click yes, the replay will be permanently deleted.
After confirming, your event will then go back to a scheduled state and you can go live again without having to create another event.