To delete all of the portraits in your database, select everyone in the database by clicking the checkbox at the top of the first row.
Warning: If you delete all of the portraits in your database, all of the portrait pages in your book will be removed as well. Only remove all your entire portrait database if you have imported the wrong set of images or data, and need to restart your panels from scratch. Deleted databases/portraits cannot be restored.
Click on Delete People on the top menu.
Confirm this request... keep in mind, it is not reversible!
When the deletion process is completed, your portrait table will disappear only if you have 1 page of portraits (max 150 people). If you are a larger school, then repeat the above steps until your portrait database is clean.
You can now re-import a new database or a new set of images.