Update Deliverable type from Client deliverable to Internal Deliverable

Our team is trying to utilize the reporting functionality, and as a result need to update our delivery maps to make more use of the internal vs. client deliverables categorizations. However, there doesn't appear to be a way to change the deliverable type from 'Client Deliverable' to 'Internal Deliverable', although it appears we can change a 'Client deliverable' to an 'event'.