Update AT&T unlocked Galaxy S4 from 4.2.2 to 4.4.2
I have an AT&T unlocked Galaxy S4(bought in US, currently using in India).
I am not getting any OTA update.
Please, suggest me a simplest and safest method for flashing the OTA update.
Also let me know, if flashing the AT&T OTA update will make my device SIM-locked?
Sent from my SAMSUNG-SGH-I337 using XDA Premium 4 mobile app