*Please note: There are bound to be bugs and glitches as this is just a beta version.You may have to reinsert your SIM card and wait a minute. You also might have to reboot your iPhone 3G again. It may not even work because this is the first day of the release. First time on the first day of the new year, 2009.  Sometimes your service will go on and off but it shouldn’t be too much of an inconvenience. Report any problems, bugs, and/or errors to the iPhone-Dev team at blog@iphone-dev.org. Happy unlocking!

Preparation

*Your iPhone 3G must have or meet the following requirements before you start:

  • Jailbroken with Cydia (Refer to this guide for the Mac and this guide for the PC if you need help)
  • 2.2 firmware
  • 0.2.28.00 modem firmware/baseband [comes with 2.2 firmware]
    If you’re not sure, go into Settings>General>About and scroll down to check. It should look like the screenshot below:

iphone

How-To

1. Run Cydia 

Run Cydia

 

2. Go to Manage>Sources. Then click Edit and then Add. Enter the custom source: http://apt9.yellowsn0w.com/

Cydia Add yellowsn0w source

 

3. Wait as the source gets added and it should be automatically refreshed (if you’re having problems manually refresh)

 

 

 

Updating yellowsn0w Source

4. Go to the Sections tab. Then scroll down to Utilities and tap it.

Utlities Section in Cydia

 

5. After that find the package named yellowsn0w and tap on it.

yellowsn0w in Cydia

 

6. Press Install then Confirm.

Installing yellowsn0w

 

7. Reboot your iPhone. Congratulations! Your iPhone 3G should have been successfully unlocked.

Unlocked iPhone 3G on T-Mobile