Need Help - Read the previous posts but it does not fix the issue I am trying to solve - which is the following:

Previously - We had one Income stream and sales invoices were all registered under the same account SalesIncome
then we added two new revenue streams SalesIncome01 and SalesIncome02 and SalesIncome became a parent category for SalesIncome01 and SalesIncome02

How can I migrate old invoices showing under account SalesIncome to exclusively SalesIncome01 or SalesIncome02 ? 

When updating the Income Account under Sales > Product/Services we missed to click on 
"Also update this account in historical transactions"
Note. Deteling invoices and recreating it is not an option, hundreds of them linked to received payments.

Thank you. Hope you can help.