Help sim carrier unlock

[Puddin454420]

Hello I just got a Samsung Galaxy S4 Active yesterday from Att and I want to use my T-Mobile sim in it and don't know anything about how to please someone help!! TIA

 

[Alex Johansson]

what baseband version and android version are you using?

 

[Puddin454420]

Baseband is I537UCUBML2 AND Android is 4.3