Check out Samsung's website for tips. You can probably send an email to them directly. Normally all you need to do is insert the T-mobile SIM and when prompted, enter the unlock code.
I got the unlock code from ATT, but each time I put in the unlock code, it doesn't work.
the instructions ATT sent me was for the Blackjack 1, the original one. they said they don't have instructions for the 2 yet.
Power off device and remove the SIM card
2Power on the handset
3Enter: # 7 4 6 5 6 2 5 * 6 3 8 * unlock code #
the screen changes to enter network key after i enter the second *
i put in the 8 digit unlock code, and click ok and it says invalid. any suggestions?