[Galaxy S 4 Q&A, Help & Troubleshooting] nuback:
##Things you need##

USB cable

S4 GT-i9505

4.4.2 firmware

I9505_XXUAME2 modem

regionlockaway

##################

1.Download stock firmware 4.4.2 (firmware found on sammobile)

2.Download Laest Odin and install samsung drivers

3.Power off phone

4.Hold power button + volume down, select volume up to enter download mode

5.Once you see the green Android and says Now downloading..you are good to go

6.plug in usb cable and connect your phone..see step 16 and 17 to see how to enter developer mode.

7.Launch Odin and make sure choose Run as administartor

8.Odin will say Added! on ur left..also you will see which com its using..can be for example COM3 or COM4...point is, its not the same for every computer

9.the latest ODin has BL, AP, CP etc

10.now lets do this! Choose AP and Load ur stock 4.4.2 firmware, odin will sometime say not responding but dont worry after a moment it will finish loading..check the logs on the left. also make sure autoreboot is check and reset time..these option are checked by default. DONOT TICK OTHER OPTIONS..JUST DONT.

11.Once loaded, click Start and Odin on top left will show you a progress bar on how much until done..this will take sometime..sit back and relax

12.once done, your phone will restart and start loading the new firmware, if stuck on samsung bootlogo continue to step 13 if not skip to step 15

13.Remove your battery and put it back on and hold power button + volume up to enter recovery mode.

14.Once you see recovery mode, scroll down using volume down, select reset cache/factory setting, press power button to select, scroll down again on YES an click power button to select, once done, go to main menu and select reboot system

15. Ok wait patiently for ur phone to load the firmware, once loaded..skip the user setting as much as possible..like setting user acc,time and date etc...

16.go to settings, more, scroll down, select about device,check os version..should be 4.4.2

17. now scroll down more and see build number..tap on that a few times until its says ur now developer.

18.tap back, in settings menu, you will now see developer options, enter developer options and check usb debugging

19.Now the tricky part, we will now change the baseband to get several option unlock in the service menu..mainly to get this option PERSO SHA256 OFF in the service menu. if most of u have upgraded to 5.01 firmware and tried every unlock method..but not working..This method works 100%.

20.Assuming all drivers working perfecty, usb debugging On, turn phone off and go to download mode, hold power button+volume down, select volume up to continue

21.now ur in download mode again, Download I9505XXUAME2 which can be found in this link http://xdaforums.com/showthread.php?t=2192025 and extract the zip file to a folder.

22.Launch ODin (run as ADministrator), make sure ur phone is added!, select CP and select I9505_XXUAME2_MODEM.tar.md5 and click start,when finished ur phone will restart

23. Almost there! :D, so now go to settings,more, about device,check baseband, should say I9505XXUAME2, if so ur good to go

24.now u can check this http://gs4.wonderhowto.com/how-to/c...y-s4-so-you-can-use-another-sim-card-0148110/ to see how to get to service menu

25.i will tell u anyways..go to dialer, type *#0011#, touch menu on phone, select key input, type 1 (sometimes i type Q0 if 1 doesnt work), press ok, press menu again, press back in menu..wait until u get the service menu, go debug screen, phone control, network lock, and there it is! the damn PERSO SHA256 OFF.click on that, u can continue to follow the guide in the link with photos where its says go back to main menu and go COMMOn, nv rebuild, restore backup..do that too.

26.now ur phone will restart and in my case it didnt unlock my carrier. what a bummer but fear not we shall continue..

27. Now you have to root this phone, iv downloaded kingoroot for this..use whatever method u like to root ur phone.

28.now assuming ur phone is rooted, download regionlockaway follow this link http://xdaforums.com/showthread.php?t=2470551 or http://xdaforums.com/attachment.php?attachmentid=2370437&d=1383564029

29.now copy regionlock to ur phone using usb cable..should be easy :D,use file manager on ur phone, install it, requires root access..click accept, launch the app, click on regionlock

30.it will say updating modem, finally it will show patch seems to be successful.blah blah blah :D..choose reboot now and thats it your done!

31.if u dont see ur carrier, go to settings, connections tab, more networks, mobile networks..choose ur carrier, wait for it to register and finally ur done :D

Note:u can update ur modem to new version because the unlock is permanent, changing firmware or baseband will not lock the phone :D ENJOY