
Step 1: You have to jailbreak your iPhone 3GS by following one of these tutorials.
Step 2: Once jailbroken, follow these steps:
- Launch Cydia.
- Add the following source to Cydia repo666.ultrasn0w.com (note there is a “0″ in sn0w, not an “o”).
- After installing this source in Cydia, search for “ultraSn0w”.
- Install UltraSn0w and reboot your iPhone.
Tha’ts as simple as that!