[How-To} Unlock Your GSM iPhone to use on Other Carriers!

[Hypnotic2010]

Ok, Thanks for the writeup OrangeKid.

So I have a 3GS that I need to unlock for other carriers like T-mobile.
It is currently running IOS 4.3.5, with modem firmware 05.16.02.

Please let me know if Ive got this right,
I dont want the tethered Jailbreak so,
-First I will need to downgrade to the latest supported untethered jailbreak which is 4.3.3 using Redsnow with the 4.3.3 Ipsw, and choose the update to the 6.15.00 baseband" option.
-Lastly I would run "ultrasn0w" from Cydia to unlock.
Does this sound the the right procedure, or am I missing anything?

Thanks again OrangeKid!