3GS Jailbreak/Unlock - Please check my facts

[DeaDLocK]

Hi everyone,

A friend has been using a 3GS that was jailbroken and unlocked by someone else over two years ago, so will be running pretty old firmware. She never connects it to iTunes or has a data plan etc - she just uses it as a phone/alarm/calendar.

I have been tasked with upgrading it for her, but I want the upgrade to give her completely pain-free functionality. Here's the conditions of the upgrade:

1) Must be fully untethered
2) No loss of functionality (e.g. GPS)
3) Should sync nicely with iTunes
4) Should function easily without any techy knowledge (no iTunes surprises, no TinyUmbrella etc)

I am not an expert, and this is my first time working with iOS exploits. But I have done some research, and based on that, this is my action plan:

1) Connect jailbroken iPhone to most recent version of iTunes (Windows)
2) Backup jailbroken iPhone
3) Upgrade to iOS 4.0.1 using ipsw file
4) Restore iPhone from backup
4) Jailbreak using redsn0w (Windows)
5) Unlock using ultrasn0w (Windows)

And then the phone should be perfectly usable, right? By that I mean she can restart it, connect and sync with iTunes etc without any problem?

Reason for 4.0.1 is that I understand this is the last version that comes with an unlockable baseband (without needing to upgrade to the iPad baseband) - am I correct?

Thanks for any advice!

[iYeow]

No, before you do any restore while iphone is bootable. Run latest tiny umbrealla, plug iphone in and request shsh from cydia, look under general for shsh blob. These shsh blobs will help you to restore , otherwise NO.

[zoolman88]

U want to make a custom ipsw in snowbreeze for windows or pwnage tool for mac u want to make 4.1 because it's still being signed by apple.
U need to make a backup of the device first using iTunes
After u have the firmware made use ireb for windows to prep the device for restore and then go to iTunes and click shift restore and pick the custom ipsw u made it will restore and ur good to got on 4.1 saving the baseband in the process and just open Cydia and install ultrasnow and u should get service back also if u want mms to work add cydia.pushfix.info to the sources and add the mms fix for tmobile and put this in ur settings wap.voicstream.com
Sorry if I was to late