Use the delete snapshot API to delete a snapshot from the repository:
When a snapshot is deleted from a repository, Elasticsearch deletes all files associated with the snapshot that are not in-use by other snapshots.
If the delete snapshot operation starts while the snapshot is being created, the snapshot process halts and all files created as part of the snapshotting process are removed. Use the Delete snapshot API to cancel long running snapshot operations that were started by mistake.
To delete multiple snapshots from a repository, separate snapshot names by commas or use wildcards:
DELETE /_snapshot/my_backup/snapshot_2,snapshot_3 DELETE /_snapshot/my_backup/snap*