In Oracle EBS, how do you update the Pay Group with new Pay Group after conversion?

Oracle EBS - Payables : how do you update the Pay Group on Supplier with a new Pay Group after conversion has happened?

I changed the Pay Group on Payable Options under Supplier with the correct Pay Group (Default) but when checking the Supplier, under Invoice Management, the new pay group is not showing. When I deactivate the flag on the Purchasing Lookup, the Pay Group becomes blank. Is there a way to update the Suppliers affected with the new correct Pay Group? Manually it can be done, but I am looking at updating a couple of hundred suppliers. Thanks