Required firmware : 3.0
Required software : redsn0w
Compatible devices : iPhone 2G
Note that this RedSn0w tutorial is for Windows users but I assume the steps are similar on a Mac.
1. Before doing anything, make sure you have the latest version of iTunes and the latest firmware 3.0 installed on your iPhone 2G.
2. Create a new folder on your desktop. In this folder, download RedSn0w as well as the latest 3.0 firmware for your iPhone 2G firmware (make sure you pick the right firmware). Also download the following bootloader files: BL 3.9 and BL 4.6
3. Unzip and launch RedSn0w.
4. Click “browse” and select the 3.0 firmware you downloaded in a folder in step 2.
5. Once the firmware has been successfully identified, click “next”.
6. Select “install Cydia” and “ulock”, then click “next”.
7. Browse for the bootloader files you downloaded in step 2, and click “next”.
8. Make sure your iPhone is plugged into the computer and that it is off. Click “next”.
9. RedSn0w will then guide you to put your iPhone into DFU mode. Hold down the power button for 2 seconds. Without releasing the power button, also hold down the home button for 10 seconds. Without releasing the home button, release the power button but keep holding the home button for 30 seconds.
10. If done correctly, your iPhone should reboot and the jailbreak process should start. This step may take up to 15-20 minutes so be patient.
11. Once this process is over, you will get a message saying that it is “done!”
12. Click the “finish” button and reboot your iPhone. The reboot may take up to 10 minutes so again, be patient.
13. Congratulations, you just jailbroke and unlocked your iPhone 3.0 with RedSn0w.