Log in to your Smart Stories dashboard.
Locate the group of stories you want to delete and click on the group to open it.
Click on "Edit Story" on the top right of your screen.
Click on the story where the tab you want to delete is located. Look for the "x" on the top right of the story tab. Please note that the "x" will only appear when 2 or more tabs have been created. To delete a story with one tab, please delete the story itself.