Changing the context type of context attribute?? but why should you do so directly on the WD context? Models of standard applications are defined by standard structures/service calls, changing them directly on the context level would have major implications for sure...
I would suggest that you analyze all the possibilities, like checking if you have any additional fields that you can re-use, or if you can add new filed on structure etc., Make best use of enhancement framework to change behavior of your application.
Br,
Nadh