There's no tool as such to my knowledge, sometimes in the past i've re-named the instant.cfg (the backup file) to instant.txt, then removed the line below (yours might have a different version number). I then re-named it to .cfg again and uploaded to the VC.
version 6.4.2.0-4.1.1
Or you could try this, however it is slightly longer.
- separate a single IAP from cluster.
- Downgrade to 6.4 version.
- Restore backup.
- Upgrade to required version.
- Export backup
- Restore backup to remaining upgraded IAP cluster.