CoreData Migration for ClouidKit

Rick Aurbach

I am upgrading an existing (CoreData-based) iOS app to support CloudKit synchronization. This doesn't work because the app includes an ORDERED relationship.
I need to perform a migration from this ordered relationship to something else that supports both CloudKit and maintains ordering. 
The problem is less about WHAT I need to do to support my requirements as it is HOW to perform the migration (so that my existing customers don't lose data.) Have you encountered this problem? How did you solve it?