For shapes that you dragged and dropped onto the page, you could edit the
Master shape in the Document Stencil. This would update all the shapes in
the diagram for a given master. Go to File > Shapes > Show Document Stencil
and double click a shape in the stencil to change it.
be aware when drawing large, complex visio diagrams to be consistant. when a
stencil is created always use repeats of the stencil. (never alter a stencil
