How to unlock sprint iPhone 5, 6.1.4 for overseas use?

I have a sprint iPhone 5, 6.1.4 that i'm currently using with sprint, how can I unlock it so it can read a SIM card from a different carrier overseas? I tried unlocking it through sprint but they told me I had to have had the iPhone for at least 90 days (currently 40 days or so), I'm only using it overseas with a different carrier not here in the US, can you help me?

This sound like a YouTube problem

There's a book for 99c that does a good job explaining it. Should definitely work for you.

Book for unlocking phone - http://www.amazon.com/...008LYE5XU/

You can try getting the phone factory unlocked and that will solve the problem. Check online for factory unlocking the Sprint iPhone 5 and not software unlocking.