Thanks for the tip. I drive a 2008 Getz with mp3-03.
I pressed Presets - 2,3,4,5 followed by "Power" button then Preset "6" and "5" and it worked.
I think Preset 6 and/or 5 are simply the "Enter" button.
It was a little trial and error process to figure what was going on. Entering 2345 followed by 5 simply changed 1CDE to 2CDE etc. I think this simply denotes 1st try, second try and third try. After that the headunit shuts down. I simply disconnected the battery, waited for one minute and reconnected it and the head unit will reboot and give another 3 trys.
Note - No need to remove head unit or add 1212 as suggested in other forums or website.
Hope the information helps.