(Minor pet peeve, people who scream for help like that, I understand, you want help, etc. But you don't need to add that many "!"s and "yell" like that. Sorry, it just bothers me a bit.)
ANYWAYS, the simplest procedure I remember off the top of my head is taking another non-T-Mo SIM and putting it into your phone. It should prompt for an unlock code, which you can then put in. Voila.
Now, how do you do that? Take off the back cover, the white cover can come off of the device, so take that off somehow.
Power off your phone by holding the power button and swiping down on the screen when it says so.
Take out the battery.
Pull out your SIM, which can then be replaced.
There might be another procedure, but I don't remember right now.