Create android class that assigns ringtone to a contact

I have an app that among other things needs to be able to assign a ringtone to a specific contact. It's a trivial task but we our outsourcing it to cut down on development time. This task would be initiated from a context menu we have built into the app already. Once the assign this ringtone to contact option is chosen from the menu, the user should be taken to his contact list, where he selects which contact to assign the previously selected ringtone. After selection, the user is returned to the previous task.