There does not seem to be a way to delete playbooks. I do not see any UI option for it, and no way to enable it in system console.
Also, his being a plugin, there does not seem to be support for it in mmctl.
We just tested playbooks and we went a little bit overboard and now we have tons of useless playbooks we can’t get rid of.
Update: The GUI refers to this functionality as “Archive”, so when you’re in the playbook editor, you can click on the heading and choose “Archive” at the bottom, to archive the playbook.
There’s no way to permanently delete it right now, the API’s DELETE method also only archives the playbook.
If you finished your testing and want to start with a fresh setup and do not care about already existing playbooks, you could truncate the relevant tables or uninstall the plugin, delete the tables and reinstall it again in order to create a fresh “out-of-the-box” experience.
I’m afraid there’s no supported way to permanently delete a playbook in the database and personally I do not know the interaction between the tables so I cannot even recomment what values to delete in what tables.