Update terms on open AP Invoices

I need to update the terms on 400 or so open AP Invoices. I have the DMT, but there doesn't seem to be a mechanism in there for that... the AP Open Load option says it can't find the record. Can the DMT do it somehow or do I need to do it through SQL? (we're on 9.04.507A SQL).

Thanks,

Ernie Lowell