Updating Exising Module

I want to add couple of new attributes to the Project model (not custom fields) and want to add a Member role for a project member.

The studio application does not seem to allow updating existing model (except for attr attribute or the custom fields).

So what is the right approach to update an existing model?
Is there a studio or similar application/plugin available to make such changes?

Thanks
Ranes

You can create new custom module, and add project module as dependency. For reference its already done for project module on business-project module.