You can only edit and make changes to broadcast campaigns that are in "Draft", "Scheduled", or "Paused" status. To edit a broadcast: 

1. Click on the broadcast in the table on the "Broadcasts" main page to access its settings page
   
   
    
2. Make the desired edits to the selected broadcast in the settings page. For more information on how to configure broadcast settings, click here.
   
   
   
   
    
3. Save the broadcast as a draft to keep any changes made, or review and publish it to send the broadcast to the selected audience