Here is a pro tip for doing this. I have transferred a TON of toons :/ Go to your WoW directory WTF/Account/oldaccountname/server/toonname <--copy this folder (Ctrl+C) the go to WTF/Account/newaccountname/server/ and paste here (Ctrl+V). Be sure to log into the toon on in it's new destination first! Overwrite all the files when you copy. This will restore your macros (even though they are serverside you still lose stuff) and your addon settings.