How to switch from one apple ID on two iPhones to two apple ID's
Hello,
So here is the thing. I have two iPhone 3gs phones right now. One has an AT&T sim card and the other has an international sim card. They are both going to be upgraded to an unlocked iPhone 5. I have never backed up either to an iTunes.
BOTH iPhone 3gs are logged into one apple ID. I want to change it so each one has a separate apple ID. So one phone will keep the same apple ID but the other will need a new one?
BUT, the most important thing for me is when I switch one of the iPhones to a new apple ID, that I DO NOT lose my messages or contacts! I found info online about switching ID's and that you have an option to keep your contacts. But I can't find anything relevant to whether I will keep or lose my messages. I don't think either iPhone 3gs has iMessage because texts I send out show up as green, rather than blue, but I am not sure.
I have no idea how to go about this and would greatly appreciate some help! Thank you!
iPhone 3GS