Changing types or stereotypes in customizing UML elements?

[Model Trainer]

Hello every body,
We've modelled the application and capability lists in UML with generic type like object and class. Now I want to change their type via exporting into a CSV file, including their GUID, and again importing them to the same diagram to change their type. I did it with their stereotypes and they were changed by this method. But the types didn't change. They are shown same as the past. Does any body know how can I change the elements' types and see their new types there?
Is it common to change type or stereotypes ro show that an element is a capability or an application?
Which languages are more compatible with UML? BIZBOK? BABOK? or ArchiMate? to set their various stereotypes for UML object or class types? Why some of the stereotypes are shown for these elements and some others not?
Sorry for many questions. Hope some body can help me with some of them.