You can delete an element one of these ways:
Select the element in the Editing Window and press Delete or Backspace.
Place the cursor inside the element in the Editing Window and press Ctrl-Delete.
Place the cursor before the element in the Editing Window and press Delete.
Place the cursor after the element in the Editing Window and press Backspace.
Right-click the element in the Editing Window and select Delete Element from the context menu.
Click the element in the ContentMap and press Delete.
Click the empty branch before the element in the ContentMap and press Delete.
Click the empty branch after the element in the ContentMap and press Backspace.
Right-click the element in the ContentMap and select Delete Element from the context menu.