Click on My folders in the side bar to manage your folders.
Depending on your version, you can also use the context-menu on the sidebar itself.
Heey, I learned something new today. 😃 Thank you. I always thought that "My Folders" is just a text title. So I never clicked it. Anyway, the option to do it directly from the list is surely a nice addition. And, at least as an ex Windows user, seems a bit more intuitive to edit/delete those folders directly from the list, rather then entering anther section and managing them from there... But nonetheless, I learned something new today. So thank you for that. 🙂