Step 1: Globally change invoice status if you use invoice approval / if the invoice distribution is not editable when the status of the invoice is approved
Step 2: Export all necessary Invoice information
Step 3: Update the Credit account in the new CSV file just exported using Find and Replace in Excel (if possible)
Step 4: Import the information to overwrite the existing distribution on the current invoices included

Step 1: Create a query of all invoices that need to be changed. 
*If you use invoice approval, you will need to change the invoice status of all to pending instead of approved if they are approved currently.
You can do that via a global change
If you do not use invoice approval, proceed to step 2

Step 2: Create the Export

1. Create a blank CSV (Comma Separated Values) file, as this will be the file you use for the export/import.
2. In Accounts Payable, Administration, Import, create a new Invoice Import.
3. Select the option to Export and fill out any required fields on the first tab. [I would recommend creating a query of the invoices that are not paid yet/in an approved status]
4. For Import file path, browse out to the file created in Step 1
5. On the fields tab, double click to select and add the following: 
Invoice Import ID
Invoice Number (use just for your reference, would need to be deleted before actually importing again)
Invoice amount
Debit account number (Invoice Distribution debit account number)
Amount (Invoice Distribution Amount)
Credit Account number (Invoice Distribution Credit Account number )
(if projects are involved)
Project ID (Debit transaction distribution Project ID)
Amount (Debit transaction distribution Amount)

*Repeat the last 5 fields in order for as many lines as the invoice has lines of distribution (up to 99 lines max)

6. Select to Create Now.

Step 3: Update the accounts in the CSV file

In the export file, make any changes needed, such as finding and replacing the old Credit account with the new
Once ready, delete the column for Invoice number and save the file as a CSV (comma delimited)

Step 4: Import the changes

1. Back in Import, create a new Invoice Import parameter 
2. Select to update exiting records on the first tab and any fill in any other required items - mark to validate data only first
3. On the fields tab, map all necessary fields, taking care to ensure that the extensions are grouped together properly.
4. Validate the import
5. Once 100% good to go - unmark to validate only and import the new information

Additionally, see How to import into The Financial Edge