create an INSTEAD OF trigger, Sales.tr_ArchiveOrders, that watches the Sales.Orders table for a DELETE and instead does the following:
1. Copies all relevant rows from Sales.Orders to Sales.OrdersArchive
2. Copies all relevant rows from Sales.OrderDetails to Sales.OrderDetailsArchive
3. Deletes those rows from Sales.OrderDetails
4. Finally, deletes the relevant rows from Sales.Orders