How to: Delete Type Shapes and Associated Code from Class Diagrams
You can delete a shape and its associated code using the Class Designer. This procedure describes how to delete both at once.
To delete a type shape and its underlying code
Right-click the shape on the design surface.
Select Delete from Code from the context menu.
The shape is removed from the diagram and its underlying code is deleted from the project, including any comments and attributes surrounding the type and any unmodeled data within the type such as regular comments, whitespace, and method bodies.