DELETE 
  FROM [msdb].[dbo].[log_shipping_secondary_databases]

DELETE 
  FROM [msdb].[dbo].[log_shipping_secondaries]

  DELETE
  FROM [msdb].[dbo].[log_shipping_secondary];

  DELETE
  FROM [msdb].[dbo].[log_shipping_primary_secondaries];

DELETE
FROM [msdb].[dbo].[log_shipping_primary_databases]

DELETE
FROM [msdb].[dbo].[log_shipping_primaries]

DELETE
FROM [msdb].[dbo].[log_shipping_monitor_secondary]


DELETE
FROM [msdb].[dbo].[log_shipping_monitor_primary]

DELETE
FROM [msdb].[dbo].[log_shipping_monitor_history_detail]

DELETE
FROM [msdb].[dbo].[log_shipping_monitor_error_detail]

DELETE
FROM [msdb].[dbo].[log_shipping_monitor_alert]