Organization spin-off : moving some open documents to new legal entity

Dear All,

As part of org restructuring we have a business requirement to move certain open invoices and purchase orders to a new instance (new legal entity).  Around 90% of the invoices are having reference to purchase orders. To avoid duplication of accounting and risk of duplicate payment, Invoices and POs those are getting moved into new instance has to be closed in the current instance.

Any suggestions ?

Thanks in advance.

Rajesh