Data Migration with CSFLE enabled

We are introducing CSFLE in our applications. We are currently on version 4.0 and plan to move to version 4.2 (standalone/replica-set) for taking the advantage of CSFLE feature.
This question is on data migration. The data is currently not encrypted. How do we migrate the data - with CSFLE enabled - so that the data is migrated live and is encrypted based on the json encryption schemas provided?
Is there a tool available? How do we enable CSFLE on the destination mongodb instance and configure the json schemas?
Is there any live migration service available? Need urgent guidance on this.