What if you decide you want a different layout altogether? You can easily switch to another one.
With the graphic selected on the slide, click the
Design tab in
SmartArt Tools. (These tools are available whenever the graphic is selected.)
Click a layout thumbnail in the
Layouts group.
That layout is applied to the graphic.
Tip: Reset a graphic If you've altered the structure of the graphic by adding and deleting shapes or done other customizations, and you want to start over, click Reset Graphic:
This resets the whole graphic. It's on the Design tab in SmartArt Tools.
If you only want to go back a few steps, you can use Undo 
on the Quick Access Toolbar.
