This simple guide will teach you how to jailbreak 3.1.2 firmware on iPhone 3G / 3GS with GeoHot’s Blackra1n as well as unlock your device for use with any GSM carrier using Blacksn0w. Just follow the easy steps given below: Step 1: Restore your iPhone 3G / 3GS to official iOS 3.1.2. – Download iPhone [...]