Watch this short video or read the guide below:
In order to edit or delete a scheduled message you will want to go to 'Scheduled' from the Dashboard.
To delete a message, click on the "Cancel" next to the message,
If you would like to edit the message you have scheduled, select it from the list of scheduled messages.
The right panel will now show the message details. You will now be able edit the message before it sends at its scheduled send time.