Otho Moji'ko at Revantusk Village in the Hinterlands wants you to travel to Aerie Peak in the western region of the Hinterlands and place the Final Message to the Wildhammer by the well in the center of town. Return to him once this task is complete.
Beware of angry Wildhammer dwarves and unruly members of the Alliance.
You take this, mon. You take this to Aerie Peak, dead center of town by the well. You plant it! Drive it right into the ground! Show those dwarves that troll mean business! Come back when you do this. Hopefully you come back alive.
I wish I coulda been there to see the look on their faces, mon. Are they packing up their bags? Leavin' town?
You done good, <name>. Real good. Otho reward you with the big mojo.