How to upgrade older Galaxy S4 Active (att) to at least Kitkat 4.4???

[AC Question]

I just got a phone from a friend that they haven't used in awhile. It's the Galaxy S4 Active i537 and is running android 4.2. I need it to run at least 4.4. Any ideas on how to get this??? Kies did not work, and bc of its age, checking for an update does not work. Please help!!!

 

[nahoku]

You might try reading THIS XDA thread.