Changing Image shape in Draw and/or Photo X7

1. I've drawn a picture of a man.

2. I've opened the scanned drawing in  Photo/Paint and, using the Cutout Lab, have eliminated the background.

3. I've decided that he needs a bigger gut/midsection.

4. How?!?

In my limited knowledge of such things I figured I could simply click a button to create an outline around the subject and simply click and drag the outline to change/enlarge the shape.

Is this task even possible? I know I've got an extremely limited Computer Graphics vocabulary but it drives me crazy.