Conversion of Instance's Ephemeral disk to Persistent disk

Issue

• A RHEL instance which was built with an Ephemeral boot disk, for reasons need to convert the/dev/vda disk to a Persistent attached volume that we can boot from.

• Are there any special tools to accommodate this, beyond, taking a snapshot of the instance, creating a volume from the snapshot, launching a new instance, and migrating any other disks over?

• Ideally, would be able to create the volume from the snapshot, somehow detach the ephemeral /dev/vda from the instance and replace it with the persistent volume if that makes sense.