How do I unlock my T-Mobile Iphone 5's?

How do I unlock my T-Mobile Iphone 5's? I have already received my unlock email through T-Mobile. I follow the instructions but I can't seem to get it to unlock? Can someone walk me through this?

When T-Mobile has unlocked your iPhone, you simply take out the T-Mobile SIM (If it is still inserted) and put in a different carrier's SIM card. The phone may "freeze" for a few seconds and take you to the setup screen where it will check with Apple to see if it is actually unlocked. If everything is successful, it should then let you use the phone.

Note: iPhones don't use unlock codes like most other phones. So if you somehow got an "unlock" code from T-Mobile, you don't really need it on an iPhone.