Use the eraser tool to delete objects from the EER Diagram canvas.
Change the mouse pointer to the eraser tool and click the object you wish to delete. Depending upon your settings, the delete dialog box should open, asking you to confirm the type of deletion.
          The delete action of the eraser tool is
          controlled by the general option setting for deletion. Be sure
          that you understand the available options described in
          Section 5.4.4, “The Model Tab” before using the eraser
          tool.
        
From the keyboard, use the D key to activate this tool.
        In addition to using the eraser tool, you can
        also delete an object by selecting it and pressing
        Ctrl Delete or right clicking
        it and choosing Delete from the pop up menu.
      

