Default [Q] Unlocked AT&T with Simple Mobile Sim. How to update software.

Hi all

I bought a Note 2 At&T unlocked from SWAPPA.

Currently using a Simple Mobile Sim. it is still on 4.1.1; Anyways to updated to 4.3?

I tried once with KIES to get to 4.1.2 only to narrowly brick. it got interrupted & fought hours to get it back to stock 4.1.1 using ODIN?

any reliable ways to update? pls help guys.. sorry if i posted duplicate. tnx