iPhone 3GS unlock 5.1.1 HELP!!!

[Johnsonjulian38]

My friend had an iPhone 3GS and wanted me to update him to 5.1.1

I updated when he told me he had it unlocked for T-Mobile.
I have been trying to re-unlock it for him using Redsnow and the older baseband so he can have GPS. What are the EXACT steps necessary to fixing his phone?

 

[PsstGreek]

What's the baseband now? You can either have AT&T unlock if you're a customer, or purchase and IMEI unlock from eBay.

 

[Johnsonjulian38]

What's the baseband now? You can either have AT&T unlock if you're a customer, or purchase and IMEI unlock from eBay.

6.15.00 due to a restore.

He is a T-mobile customer. Is there another way to unlock? I've tried jailbreaks but they are rendering his phone with no service.

 

[PsstGreek]

6.15.00 due to a restore.

He is a T-mobile customer. Is there another way to unlock? I've tried jailbreaks but they are rendering his phone with no service.

To unlock you'll need to downgrade the baseband using the newest version of rednsn0w http://www.ijailbreak.com/how-to/downgrade-06-15-00-05-13-04-iphone-3gs-3g-redsn0w-0-9-14b1-windows/

Then you can either jailbreak and unlock with ultrasn0w (software) or get an unlock like the way I stated in my first reply.

 

[Johnsonjulian38]

I have downgraded before, but would still get no service on his phone with the ultrasnow unlock, and it seems a lot of people get the error.