I tried updating my phone to 4.4 kitkat with this method :
Files required: download the UCUFNB1 Android 4.4.2 KitKat
1. Change the name of 2400258.cfg to update.zip.
2. Copy the update.zip file to your Galaxy S4 via your PC, in the root folder.
3. Disconnect the phone from your PC and boot into recovery mode.
4. Click on Apply Update.zip option, to run the update file present in the internal sd card.
5. Just wait till the process finishes up and the update is installed on your phone.
Unfortunately I do not see any " Apply Update.zip option, to run the update file" in recovery mode.
So i'm clueless what to do? They lauched kitkat many months ago not sure why my phone does not pick it up.
Thanks in advance!