Need info on how to unlock my Samsung Galaxy Note...

Hey all, my wife and I are unfortunately leaving Korea suddenly due to a family emergency and I have a cell phone question I'm trying to get some answers on. My wife purchased a Samsung Galaxy Note a few months back with Olleh and as we are now leaving, we're not sure if we can get it unlocked for use in the USA or if we should just sell if off before we go. 

Anyone with experience in how to get the phone unlocked and if so, can they be used abroad with Sprint or Tmobile? I've run searches but eveythings wishy washy maybe because this model is relatively new. Thanks in advance for the help.