As of this posting, Apple is still signing 8.1.2 for all devices - than can change any second https://ipsw.me/all
Download the 8.1.2 IPSW, then restore using option key plus restore (for Mac) or shift key plus restore (for PC) to navigate to the IPSW on your desktop. http://theiphonewiki.com/wiki/Firmware
As of this posting, Apple is still signing 8.1.2 for all devices - than can change any second https://ipsw.me/all
Download the 8.1.2 IPSW, then restore using option key plus restore (for Mac) or shift key plus restore (for PC) to navigate to the IPSW on your desktop. http://theiphonewiki.com/wiki/Firmware