Linking down payment to invoice after import

Hi all,

We have imported A/P invoices without any down payment into the system.Now client says he has some down payments which are to be linked to the invoices.

The simple thing is to reverse the Invoice and repost with down payment but it is tedious as the no.of records are more.

Is there any other work around for this?if not i have to tell him to reverse the invoices which he doesn't want to do

Please help

Thanks

Md.nazeer shaikh