Click Data Lists and then click Lists in the administration menu. The following page will show the list of Lists.
Check the in the delete column next to each List you wish to delete.
Click the Delete button at the top or bottom of the list of Lists. On the following page, you may uncheck the box next to any List that you do not wish to Delete.
Click the Delete button at the top or bottom of the list to finally delete the List(s) you've selected.
Click Data Lists and then click Lists in the administration menu. The following page will show the list of Lists.
A confirmation page will appear with a link back to the list of Lists.