iPhone 4 unlock without updating iOS

[RodChester]

Hi there. I will be getting the new iPhone 5 this Friday and I am looking to sell my iPhone 4 on ebay. I want to sell it unlocked to help get the most money that I can. I sent my request in to AT&T for the unlock, but did not receive it until this evening after iOS 6 was already released. I want to be able to keep iOS 5.1.1 so jailbreaking is still an option for the buyer and apply the unlock.

From what I am reading I need to plug my iPhone into iTunes and restore it which will unlock the phone. However, since iOS6 is now out I am worried that unlocking my phone and updating to iOS6 will go hand in hand. So after all of that my real question is can I unlock my phone through iTunes while staying on iOS 5.1.1? Any help will be much appreciated.

 

[Applejuiced]

You can deactivate it by using redsnow and activate it again using itunes.
If you're on stock 5.1.1 you can do an erase all to delete your stuff from it.

 

[RodChester]

But won't iTunes force me to upgrade to iOS 6 when I do the restore?

 

[wonderspark]

I'm trying to do the same thing with my 3GS... unlock from authorized AT&T unlock, but keep 5.1.1. iTunes wants to update the phone to iOS 6, which I do NOT want.

I'm still searching for the answer on how to do this.

 

[wonderspark]

Update:

I checked the IMEI status websites, and they all said my iPhone was unlocked. I inserted an old prepaid O2-UK SIM that I used in my Android phone in England, and restarted the iPhone. It booted up, showed T-Mobile as my network, and shows O2 as my carrier in the Settings menu. I even got a notification of my remaining credit in British Pounds on the SIM, and a "Welcome to America, enjoy your trip" text!

Never restored in iTunes, nor saw a message on iTunes saying my iPhone is unlocked, but other SIM cards work, and I'm still on 5.1.1 with proper mapping. Soooo happy!

Cliff's Notes: Wait 24 hours after email from AT&T saying unlock is approved, and use a new SIM card. NO NEED TO RESTORE / NO NEED TO UPDATE TO iOS 6.

Also, my phone is not hacked nor jailbroken. I just skipped the restore in iTunes instructions.