Use this procedure to remove a ring from a material boundary.
A material boundary can consist of more than one closed ring. You can remove each ring individually.
Note: You cannot remove the last ring from a material boundary.
- Select the 2D section with the material boundary to change, and click
. 
You are now in edit in place mode. The material boundary is highlighted and the grips are displayed.
- Click : .
- Select the ring you want to remove.
- To exit edit in place mode,
if you want to.. then click… save all changes
discard all changes