SubscribeEnsure you have upgraded to iPhone OS 3.0
Jailbreak your iPhone 3G using redsn0w or PwnageTool (this will also install Cydia/Icy)
These are instructions on how to jailbreak your iPhone 3.0 iPhone firmware using RedSn0w for Mac. This tutorial can be used to jailbreak before applying the UltraSn0w unlock.
| Step One Create a folder on your desktop called Pwnage.
Download RedSn0w from here and place it in the Pwnage folder. Likewise, download the latest 3.0 firmware from below and place it in the same folder. 3.0.0 (2G): iPhone1,1_3.0_7A341_Restore.ipsw 3.0.0 (3G): iPhone1,2_3.0_7A341_Restore.ips |
Extract the redsn0w application from the RedSn0w zip file to the Pwnage folder.
Step Two Connect your iPhone to the computer and launch iTunes.
Select your iPhone from the list of devices on the left. Now hold down shift and click the Restore button. Restore is preferred as it won’t create any wasted space on your iPhone.
Navigate to the Pwnage folder on your desktop and select the firmware ipsw.
Click the Open button to continue.
Step Three Once iTunes has finished updating
your iPhone to the desired firmware you may launch redsnw0w.app from the Pwnage folder on your desktop.
Step Four Once RedSn0w opens click the Browse button
Step Five Select the firmware ipsw we placed in the Pwnage folder on our desktop then click Open 
Step Six Once the firmware has been verified click the Next button to continue.
Step Seven Make sure Cydia is selected and click the Next button.
Step Eight Please plug your iPhone into the computer and make sure its OFF then click the Next button 
Step Nine RedSn0w will now guide you through the steps to get into DFU mode.
Hold down both the Home button and the Power button for 10 seconds.
Release the Power button and continue holding the Home button until RedSn0w detects the device.
Step Ten Your iPhone will now reboot
Step Eleven RedSn0w will then begin uploading the new RAM Disk.
Step Twelve Once this is complete you will be notified that RedSn0w is done. Click the Finish button. When your iPhone finishes reboot (5 minutes or so). It will be jailbroken with Cydia on the SpringBoard.
Run Cydia or Icy on Your iPhone 3G
Please add the repo repo666.ultrasn0w.com to Cydia or Icy. That last “o” in “snow” is actually the number zero “0”! If you use the letter “o” you’ll get an error.
Search for ‘ultrasn0w’ in cydia or icy and install ultrasn0w
Reboot your iPhone 3G
T-Mobile USA users should disable 3G before using ultrasn0w
Please note that UltraSn0w currently does not unlock Apple’s new iPhone
3GS.
Please let us know if you were able to successfully unlock your iPhone 3G.
