Deleting a Model 
The model to be deleted is not open in any Storyboard.
Choose or click the
(Manage Models) button
in the main toolbar. The Model Browser dialog box is displayed.
In the model hierarchy, drill down to the model to be deleted and select it.
Click the
(Delete) button in the toolbar. A Confirm delete message is displayed.
Note
If a confirmation message is not displayed, choose tab, and select the relevant Request confirmation before deleting checkbox.
Click Yes to delete the model.