Please read the whole post before starting. Put the file supersu 2.46.zip somewhere on your device/sd card. Power off the device. Boot into download mode (volume up + home + power) and use Odin to flash the latest TWRP in the AP slot. I recommend before flashing it go into the settings of Odin and uncheck "Automatic reboot" or something along those lines. Then when it is done it will say PASS in green. Now unplug the phone from USB and pull the battery. The phone is now powered off so put the battery back in now. Now boot into recovery (volume up + home + power) and you will be in TWRP, simply flash the Supersu file and you will have root access. I recommend wiping cache/dalvik after flashing the supersu zip but probably not 100% necessary.
I did notice that once rooted, the options for PRL update and Profile update are missing. If you have TWRP installed but the phone is not rooted, PRL update and profile update work fine. So what I recommend doing is before flashing supersu to gain root access, make a nandroid backup that way if you ever want to update prl/profile you will be able to restore the unrooted backup and do it.