Click on the Grouped object.
Click the Ungroup Selection button.
This will ungroup the currently grouped objects.
Any objects that were merged will now return to their previous state.
Click on the background mat to unselect the objects.
For Additional Information:
Select the desired object and click on the Ungroup Selection button in the Advanced tab.
Select the desired objects and click on the Group Openings button in the Tools section.
Select the desired object and Right-Click select Ungroup Selection.
