HOWTO: From iPhone 3GS 3.1.3 Spirit Jailbreak to iOS4 Sn0wbreeze아이폰 3Gs 3.1.3 Spirit 탈옥을 iOS4 SnOwbreeze로 바꾸는 방법 WARNING: NO warranty is provided with this guide. Follow at your own risk. A lot of info that iPhone 3GS 3.1.3 with Modem Firmware 05.12.01 can only be jailbroken using spirit jailbreak and no way to upgrade to iOS4. Here’s a full unlock of iOS4 when you’r..