Go to Featherbeard's Hovel and visit the dwarf if he is at home. If he is not at home, search for evidence of where he can be found.
When I am finally granted an audience with Falstad Wildhammer, I hope to have our strongest advocate among the Wildhammer dwarves at my side, [player].
Featherbeard is revered among his people, both for his legendary gryphon training skills and for his wisdom. If anyone can sway Falstad Wildhammer, it is he.
I would go to see him myself, except that I cannot leave the confines of Aerie Peak while awaiting my audience. Visit Featherbeard at his residence to the south and ask if he will speak with me.