I could really use some help unlock my little brothers 3gs

[CrazyFloridaBoy]

I, myself have an iPhone 4 but my little brother just got a 3gs and it's currently on 4.1 and the baseband is 05.16.02 and he needs it unlocked for t-mobile.
I am just looking to unlock it. I don't care to upgrade the firmware but if it is possible to unlock it and have 5.0.1 I wouldn't mind doing that.
Can anyone help me or explain to me as what I would need to do as I am not very good with this kind of stuff.
I am new to jailbreaking and all of this. I recently just jailbroke my iPhone 4.
Any help would be muvh appreciated
Thanks in advance.

[Susty]

For starters, do you know if it's a new bootrom or an old bootrom?

If your using windows, check with a program called f0recast

[CrazyFloridaBoy]

I don't know how to do that? Is their a method if finding out without using a computer?

Do you have a link for f0recast?

Ok in used f0recst and it says the boot loader is 6.4_m3s2 so is that a new boot loader? And also f0recast says it is unlockable by upgrading it to iPad bb. If anyone can help me with simple instructions I would be so grateful.

[Susty]

Ok, if you download redsn0w 0.9.10b3, you can use that to upgrade the baseband & install the jailbreak for ios5.0.1

[CrazyFloridaBoy]

The one I found online is b5 will that work

[b0bab0i]

What are the first 5 digits of the serial? I can tell you the Bootrom.

And if you want iOS 5.0.1 unlocked you first update the phone to 5.0.1.
After that use redsn0w 0.9.10b3 to jailbreak the phone and install iPad BB.
After its jailbroken and iPad BB is installed, go into Cydia and download ultrasn0w 1.2.5

Phone should be unlocked.

But beware once installing iPad baseband, you can never go back. You will lose GPS capabilities and if you want to restore the phone you have to use custom IPSW.

[Susty]

It's the new one