To delete a container without its content, press ALT+Delete or choose the Delete without Nested Elements item from the ribbon Home tab / Clipboard group / Delete dropdown button. Alternatively, you may right-click on the element in the diagram and choose Delete submenu and then click on Delete Without Nested Elements.
Delete Container Without Nested Elements
Containers are elements which may contain other elements. By default, if you delete a container its nested elements will be deleted together with it. However, Software Ideas Modeler offers an option how to delete a container without its nested content.
Delete without nested elements