Navigate to pantherlist.uwm.edu. You will land on the home page. On this page, on the right hand side of the page, there is a list of commands, one of which is Delete a List.

Click on the link, and you will be presented with a list of pantherLists for which you are the owner. Click the checkbox next to the list(s) you would like to delete, then click Next.

Click on Delete to complete the action.