[Q]Help me to unlock LTE B4 on OP3 A3003 (Please)

Hi, this is my first post ^_____^

I live in Argentina, in a trip in Italy I bought that phone, because here in Argentina phones and all technological stuff is really really expansive, my OP3 here is worth 12000AR$ (750€)
My phone hasn't B4, the frecuancy used by all the providers here in Argentina, so i want to unlock it!
I've searched on xda tutorials about how to unlock LTE Bands on qualcomm chipsets but i have a problem
What I already did:
-Unlocked bootloader, root, installed TWRP Recovery
via the toolkit http://forum.xda-developers.com/onep...nlock-t3398799

-Installed QPST
-Installed QXDM
Enter in EngineerMode via the code *#801# and actived Rndis,diag switch
Now, OP3 isn't recognized by my pc in diagnostic mode, in device manager I can see that my pc shows it as "Android" with a yellow triangle in the right corner.

I followed this tutorial
http://forum.xda-developers.com/gala...ds-to-t2886059

Should I try with this one?
http://forum.xda-developers.com/show...&postcount=455

Should I install a custom kernel like this one?
http://forum.xda-developers.com/onep...ernel-t3404970

Help me please xoxoxo, Axel