how to merge 2 operating units and 2 sets of books

 Dears, We had 2 operating units: mobile phone operator and internet provider. We kept accounting records in 2 sets of books in GL. Now we have to merge it: PO, AP, AR operating units and GL sets of books. Currency, chart of accounts and calendar are the same in both sets of books. What is the best way to merge it?   Thank you in advance for your time and help. Best Regards,

We had 2 operating units: mobile phone operator and internet provider.

We kept accounting records in 2 sets of books in GL.

Now we have to merge it: PO, AP, AR operating units and GL sets of books.