Cyanogenmod 11 - Cyanogenmod + Android 4.4.1 KitKat
Cyanogenmod is a popular 3rd party aftermarket firmware for Android devices. Cyanogenmod is also the base of most custom ROM's for Android as they always release new versions and debug the bugs. Anyways Cyanogenmod is the first source to publicly release Android 4.4 including the newest 4.4.1. Their ROM with android 4.4 is called Cyanogenmod 11, to get this go to Cyanogenmod's downloag page. Then search for your device, via its code-name. Now click on nightlies and you should see Cyanogenmod11 with 20131312 or the date of the day you are going to put the rom on the device which is the latest nightly for your device. Note that Cyanogenmod nightlies well have some bugs but will be fixed soon hopefully via their next nightly. You must have your device unlocked and preferably S-Offed to flash Cyangenmod. If you don't know how Google it or search XDA forum which is a community for Android users and developers including windows phones. If your a developer a link to Cyanogenmods source code well be here.
In no way am I responsible for your actions causing your device to fail. I am just a blogger.
Cyanogenmods website - Link
Cyanogenmods source code 4 developers @ Git - Link
Androids homepage - Link
XDA-Developers Community for (learn how to get ROMs and custom firmware on your device!) -Link