[Skunkworks] Unlock Blackberry Curve 8520

All, A friend of mine has a Blackberry Curve 8520 locked on T-Mobile and since he believes am a guru gave it to me to unlock. Am really not a fun of Blackberry's so I have no idea where to start, but since I know people who know people - I offered to help - so goes my question - anyone have an idea of how to unlock this? ./Ok3ch