Deleting a Neptune Snapshot
You can delete a DB snapshot using the Amazon Web Services Management Console, the Amazon CLI, or the Neptune management API:
Deleting Using the Console
- Sign in to the Amazon Management Console, and open the Amazon Neptune console at https://console.aws.amazon.com/neptune/home - . 
- In the navigation pane, choose Snapshots. 
- Choose the DB snapshot that you want to delete. 
- For Actions, choose Delete Snapshot. 
- Choose Delete on the confirmation page. 
Deleting Using the Amazon CLI
You can also delete a DB snapshot using the Amazon CLI
        delete_db_cluster_snapshot command,
        using the --db-snapshot-identifier parameter to identify the snapshot
        you want to delete:
For Linux, OS X, or Unix:
aws neptune delete-db-cluster-snapshot \ --db-snapshot-identifier<name-of-the-snapshot-to-delete>
For Windows:
aws neptune delete-db-cluster-snapshot ^ --db-snapshot-identifier<name-of-the-snapshot-to-delete>
Deleting Using the Neptune Management API
You can use one of the SDKs to delete a DB snapshot by calling the DeleteDBClusterSnapshot API and use the DBSnapshotIdentifier
      parameters to identify the DB snapshot to be deleted.