Once you are on the Dashboard, click on Composites tab on the left. Find the Composite project that you want to edit, then click on the drop down arrow to the right under the work Actions. Click on Delete Element from the dropdown that appears.
If you have more then one element for that Product Designer project, it will only delete that one element. If you only have the one element for that project in Product Designer, it will delete the project completely from the PLIC apps as well.
