You can delete an instance that you no longer use.
In the left frame of the CIM WorkShop window, right-click the class from which you want to delete an instance.
In the pop-up menu, click Instances->Deep Enumeration to list instances of the selected class and its subclasses. Click Instances->Shallow Enumeration ot list instances of the selected class.
In the Instance window, right-click the instance you want to delete and click Delete Instance in the pop-up menu.
The instance is deleted.