mobile

Hi, i bought an LG G2 with the model number at the back saying LS980, from sprint, but when i go to settings to see the software version it says that its D802 with rayglobe flex 3.5 running 4.2.2 jelly bean.

I want to update to at least kitkat 4.4, but i dont know from where to start...

As extra info. Im using my G2 with another carrier... So i dont want to lose my unlocked functionality. I did a bit of research on the subject and by what I've read when people remove the D802 and put the stock firmware they lose their modem/wify functionality and some other stuff happens to the cellphone.

So thats why im saying " i dont know from where to start..." hope someone can shed some light on this subject and point my to at least the starting point.

Thanks!