Replying to ON3P binding mounting

hello,
i just got a set of ON3P Billy Goats 189 and am going to mount marker jester 16 on them.
I am from Australia so have very incompetent mounters. So want to tell them exactly where to mount.
Where should I mount the binding to line up should I use the mark on the ski?
I am am ex racer so will use the ski for predominantly powder and the odd groomed run and chop when getting back to lift. Will never ski switch.
Thanks for your help.
Brent