2007 Prado Timing Gears

Hi Everyone

I am hoping that there is someone out there that can help me, I have a 2007 Prado D-4D 3.0 and I do not have any timing marks on the Timing Gears, that being said how does one set up the timing?  for example, will I have to ensure that the woodruff key on all of the shafts are point at 12 o'Clock? Or is there something else that I need to do, your help will be most invaluable

Regards Mark