1- Download and copy to SD card SuperSU Update zip
https://download.chainfire.eu/921/SuperSU
2- Download TWRP tar file for your device to your PC. Get the 3.2.0-2 IMG.tar
https://dl.twrp.me/klte/
3- in Odin, unchecked Auto Reboot in options
4- Connect phone in download mode to PC and when you get a Blue Active Com Port, select AP and find the TWRP img tar and select it.
5-odin will give you a Start button after it checks everything out.
6- When flash is complete and you get pass with Odin, unplug phone and remove the battery.
7- Replace the battery and boot into recovery mode using the button combo. Volume up + Home + Power. Should be TWRP recovery.
8- Select install, choose storage SD card, locate the SuperSU Update zip and select it. Swipe the arrow at the bottom to flash. Reboot system.
9- Open SuperSU app and let it update its binary
10- You are rooted. Check with root checker app.
11. If all goes well, boot back into TWRP and make your first backup.