Once the plugin is up and running, to remove a item from the database:

To remove a item from a database, first execute this command /dailyshop admin gui, this will show you all item entries and what category they are in!

Once you have found the item you want to remove, if you clicked on the item, it should delete it!

There is a config option to have a confirm screen before deletion!

To enable it head to your config.yml (/plugins/DailyShop/config.yml), and you should see it in the settings: section, just set confirm-delete: to either true (to enable it), or false (to disable it).