Mass Apply DMT created credit memos

We have thousands of AR invoices stuck open for discounts that the customer took but were not entered at time of payment (EDI payment import issue being worked on).

So my task is to create credit memos with DMT and then apply them with DMT.
I have successfully created a AR invoice credit memo with DMT, but now am struggling to figure out how to apply it through DMT.

Has anyone else already done this?

Brad