Replace activity in Xaml


I have a package(1) with some activities. I needed to add some more, so I took all the activities from package(1) and created a new one(2) where I have lots of others activies. I need now to delete package(1) but then the old activites dissapear. I have same ones in (2) but even replacing the name in Xaml doesnt work. Is there a way to avoid doing it manually?

Best Regards,