Unlock iPhone 4S AT&T baseband 3.0.04 on 6.0.1 with IMEI Unlock?

I have iPhone 4S with modem firmware / baseband 3.0.04 running iOS 6.0.1 locked to AT&T, how could I make factory unlock to it?

Call AT&T.

You can make IMEI factory unlock to your iPhone 4S on any iOS version and any baseband version. This is the best solution for your case. The iPhone dev-team has also recommenced to make IMEI factory unlock as they couldn't update ultrasn0w to work with higher basebands.

Important note: Be Careful, there are many scammers claiming that they able to unlock your iPhone.

How to unlock your iPhone:

Step 1: Get IMEI of your iPhone (dial *#06#)

Step 2: Send it to trusted unlock service provider, here's trusted one: http://myimeiunlock.com/shop/usa-iphone-imei-factory-unlock/

Step 3: Wait for 6 hours until they unlock your iPhone, then connect your iPhone with iTunes, then you will get confirmation message that your iPhone has been unlocked. Done.

You can do what Jasmine told you, or you can email me at stefan_zxcvb@live.com for half the price.