Manage element sets by clicking on the Settings button in the right corner of your dashboard, or by going to, /admin/settings. The Element Sets tab allows you to review and delete element sets available in your Omeka installation.
Deleting an Element Set
Deleting an element set removes all fields associated with that element set from your database, and removes all data in items that were added to those fields. Unless you've backed up your database, this data is not recoverable.
To delete an element set, simply click on the "Delete" button beside the element set you wish to delete.
Adding New Element Sets
New element sets can be added with plugins. See Creating an Element Set for more information.