If you find that a To Do List you created is no longer needed you can Delete it from the workbook. Select 'Delete' in the My To Do Lists section of the ribbon. After clicking that option you are presented with a list of To Do Lists in the workbook that can be deleted, either select the To Do List and click 'Delete' or just double click on the To Do List and the list will be Deleted.
If you have a large number of To Do Lists, you can click on the headings in the select To Do List form to sort by that heading and make it simpler to find your list. The current number of items for a list is displayed on the form.
Once selected you need to confirm the Delete, this cannot be undone so once you click 'Yes' to confirm the list will be deleted and all configuration removed.