If it's anything like mine:
* Put keys in ignition and only turn 1 or 2 clicks to power the radio
* Turn the radio "off" if it is on
* Press and keep holding the FUNC button
* Press the On (or Source) button and wait a few seconds
* Let go. The clock should flash
* Use the up/down left/right to get the hours and minutes.
(On mine, when I get the flashing clock and let go, I get other options instead, but I have to go left / right to get back the flashing clock).
Dave, in Auckland, October 2008