Best way to restore & jailbreak/unlock iphone 3gs?
I just bought a used iphone 3gs off of craigslist, and want to restore it to factory defaults before jailbreaking and unlocking it again (and if possible, do so with an untethered jailbreak.
Phone : iphone 3gs
modem firmware: 5.11.07
I was told this is a newer iphone, and has the new boot rom. If i restart the iphone, I'll have to jailbreak the phone.
Is this the best way to go about restoring the phone?
1. restore phone with 3.1.2 firmware in itunes
2. find a person with att sim card, put in iphone, and use spirit to jailbreak. (is it this easy to get past the activation screen?)
3. use blacksn0w to unlock.
Is there a better version I can upgrade to and still come out with an untethered unlocked iphone?
Sorry for all the questions - just need some guidance. I haven't done an unlock and jailbreak since the iphone 2g... so it's been a long while! Please let me know if additional information is needed.