Go to the Management screen. From there, you will click on Yearbooks for PLIC Books or Composites for PLIC Elements on the left hand side. After you have found your school, click on the dropdown icon next to the green Yearbook or yellow Subjects button. A dropdown with some options will appear. Click on Delete Project.

A prompt will appear to make sure you are deleting the correct project. Once you are sure the project name matches the name of the project you want to delete, check the box and click Delete.

Please note that deleting a project is permanent. After you delete it you will not be able to access it ever again.