Enter the inn and just to the right is a board on the floor (it looks like a washboard). To complete the quest, click on the "Blight Orfans Donashun Tin" next to the board and 50 will automatically be deducted.
You lose 50 , but completing this quest opens up more quests on the Blight Orfans Notis Bord.
pc As of patch 1.05, if you click on the notice board after completing this quest, it won't yield any more quests. Simply leave the inn, come back and try again.