[Q] Merge messages from two phones topic

My G2 was bootlooped so I switched back to my GNex for a couple weeks since I didn't have any time to repair it. Now that my G2 is back up and running, I want to add all of my new sms/mms that I got back into my G2 without overwriting the old messages. Any suggestions?

I also want to add that this applies to group messages as well.