1. Perform a full db backup on the DR DB using postgres tool: https://www.postgresql.org/docs/current/backup.html.
  2. Stop application services on the primary.
  3. Unregister primary and standby db from the cluster.
  4. Register primary the same way as in Configure REPMGR – Primary Node
  5. Restore the DB using the backup from the DR.
  6. Register standby the same way as in Configure REPMGR – Replica Node