Hi, well the way i found to get updated was to flash XXJM1 with Odin 1.0 (you need download mode key press to work 'Hold volume down and home then while still holding those press power - It will power into download mode if you have the option in your bootloader version). Do not be tempted to enable download mode from adb shell as it won't work that way if you have no holds enabled, also if you do that you could really easily brick your phone. If you have download mode you have nothing to fear!
Once completely flashed wipe all data/factory reset then wipe cache data from the recovery menu it boots into after flash (volume up/down to navigate menu, home button to confirm. When it reboots you will have XXJM1 running.
Now plug that into kies, select firmware upgrade and bingo!
XXJM1 is offical other are not so the updater doesn't consider you upgradeable