how to unlock an apple iphone 6 from at&t

Contact AT&T and request an unlock, they will walk you through the process.

Here is what one that I did looks like when the request came through via email

Unlock request number: XXXXXXXX

Thank you for contacting AT&T about unlocking your mobile device.

Congratulations! Here are your unlock instructions:

For iOS 7 or later devices, please turn off Find My iPhone before unlocking your device.

1. Open iTunes on your Mac or PC and verify that you have Internet connectivity.

2. Ensure the original SIM card that came with this device is inserted in your iPhone.

3. Connect your iPhone using the dock connector to USB cable that came with your iPhone.

4. Backup and restore your iPhone using iTunes. For information on backup and restore, please visit http://support.apple.com/kb/HT1414.

5. After restoring, your iPhone will be unlocked.

Additional information on unlocking can be found at http://support.apple.com/kb/HT5014.

Questions? Please call 800.331.0500, or dial 611 from your AT&T wireless phone.

Sincerely,

AT&T Customer Care Team

How to unlock your iPhone for use with a different carrier - Apple Support

Contact AT&T and request an unlock.

Here is the AT&T unlock request site: http://www.att.com/esupport/article.jsp?sid=KB414532