I have to start out by saying that my phone is Sprint Samsung S4(SPH-L720). I’m not sure if this is going to help you. I came here for help. Hoping that I can help out because this site has helped me so much the last four year I have been here. And of course I’m not responsible in anyway for what you do to your device. Just posting what I did to fix my phone. Programs used Win7 64-bit (WIN XP should work), Odin3 v3.07, EFS_Professional_2.0.72, QPST 2.7 Build 422, HxD, DFS CDMA Tool Demo.
My old phone and new phone I bought did not have knox bootloader on them.
First thing I did to both was flash (Oldest Firmware) SPH-L720_MDC_Rooted_Restore.tar.md5 with Odin3 v3.07. Updated both SuperSU and BusyBox from PlayStore on both phones.
Then I used EFS_Professional_2.0.72 to Backup all NV Items from new phone that had cell service. Turned phone off and pulled battery. Then Formatted all NV Items on old phone and restored backup from new phone. Restarted and had cell bars in status bar. So I knew I was good to good with flashing my service back on the device.
Using QPST 2.7 Build 422, HxD, and DFS CDMA Tool Demo verison will work just fine to do what you need to do. Go to Device Manager and find what com port your device is on. Open QPST Configuration click “Add New Port…” the com port will not be visible but if you type “COMXX” in both port and port label it will be added to qpst configuration. Example is my port COM23 so I added COM23. Close window and open DFS connect com and send spc and pwd close DFS. Note: “You have to send SPC then Pwd with DFS before using any programs on QPST.” Open EFS Explorer send spc go to directory nvm\num copy items 0 85 1943 to desktop. Use HxD to zero out items. Then delete items from nvm\num directory on EFS Explorer. Then copy the zeroed out items back to phone. Reset phone and open DFS and restore original setting that came with the phone. You should be able to restore MEID, ESN, SPC, and IMEI with DFS.
I hope XDA Developers will understand that this is just restoring your phone back to original state. That is exactly what I did. Hope this helps you.