How do you change package name in ai2 sources?

[Anke]

Not sure, if this still works:

App Inventor Tutorials and Examples: Package name | Pura Vida Apps

But this works. I did it several times.
(But it's a bit tricky.)

Example:

Note:
Of course I know that you can change the packageName at Kodular. But sometimes the (old) tough method is needed to make everything work properly.