In the Navigation Pane, click Lists, and then click the custom list you want to delete.
On the Edit menu, click Delete Custom List.
If one or more items stored in the custom list are used in any list reference fields, a Warning box appears.
If you are sure you want to delete the list, and references to the list, click Yes.
If you have a custom field that use items from the custom list, that custom field is also deleted when you delete the custom list.
You cannot delete the lists that were installed with FieldWorks.