The day is finally here! Just yesterday, Apple released the much awaited iOS4 and shortly after the iPhone Dev Team released a new unlock and jailbreak for OS 3.1.x and OS 4.0. NOTE: For now, the redsn0w beta release supports only the iPhone3G and iPod Touch 2G at today’s 4.0. It’s still a beta, so you’ll need to let Cydia reorganize, reload, and update after using redsn0w.INSERT YOUR T-Mobile SIM CARD INTO YOUR iPHONE 3G BEFORE FOLLOWING THE DIRECTIONS BELOW!1:
Download iOS 4 for your iPhone 3G here
and save to desktop2.
Update to iTunes 9.2 if you haven't already: http://www.apple.com/itunes/download/
Then in iTunes, restore to 4.03.
Download redsn0w 0.9.5 BETA for Mac here
Download redsn0w 0.9.5 BETA for Windows here4.
Launch Redsn0w 0.9.5b5-3 and point it to the original iOS 4 firmware file for iPhone 3G to proceed (download link in step 1)5.
Now select “Install Cydia”, "Enable Multitasking" and "Enable Wallpapers" and click NEXT6.
Now make sure your device is both OFF and PLUGGED IN to the computer before you click “Next”.7.
And then just follow the directions, its quite straight-forward8.
After it is done jailbreaking, your iPhone 3G will reboot automatically9.
Now to unlock OS4, you will need to launch Cydia. Let it update first then after it is done updating it will ask to restart. After restarting, launch Cydia again. Go to Manage>Sources. Touch on “Edit” and then on “Add”. You will be prompted to enter a URL source. Type in: http://repo666.ultrasn0w.com
and press “Add Source”. 10.
After installation is completed. Search for: ultrasn0w
in Cydia and install this application. This app will automatically unlock your iPhone 3G so that you can use it with any GSM carrier.
And you're done! You now have an iPhone 3G jailbroken and unlocked on the newest OS 4.0!
If you guys have any problems, don't hesitate to ask.
And as for 3GS users, the necessary tools will be released soon. UPDATE:
Apple has released OS 4.0.1 to address signal calculation issues for the iPhone 3G/3GS/4. Redsn0w and Ultrasn0w will still work
You can use this redsn0w 0.9.5 (download link above) to jailbreak 4.0.1 on iPhone3G. Just point it at the 4.0 IPSW (download link above)(Yes – point it at the 4.0 IPSW even though you're at 4.0.1).
This will also hacktivate your iPhone3G at 4.0.1 if you haven't already been activated by iTunes. Install ultrasn0w if you need a carrier unlock (and in the USA, remember to turn off 3G mode in Settings→General→Network).