1. That's likely the best option. The other option would be to do a lookup subjects call, compute the intersection of the members of the lookup call and the members of the "new" role, delete the relationships outside of that intersection, then write the "new" member relationships. 2. I wouldn't delete one at a time. The DeleteRelationships call is atomic and supports bulk deletes. It's likely your best option. Do be aware, though, we are aware of some scalability issues with DeleteRelationships that you can hit when deleting very large amounts of data (millions of relationships).