As part of the editing features of Famicity, you can remove a story you have written at any time.
For this, once you are looing at the story you want to remove, click the "..." button (1) at the top right of your story.
A menu will appear, and there you can click "Delete" (2).
A new window will appear to confirm. Once your choice is confirmed, your story will be permanently deleted.
Warning, you can only delete the stories you wrote.