Removing a Class 
In the Project Explorer view, expand the rules composer DC node, the Rules Modeling node and double-click the Aliases node.
In the Project Aliases Editor that appears, choose the Class Aliases tab and choose Remove Class button.
In the screen that appears, expand the Java Package node and choose a Java class. Choose Finish.
Note
When you remove the Java classes from the rules composer DC, you can still view the Java classes in the Java DC. If required, you can add them again in the rules composer DC.