Head´n Shoulders

So there's a blonde 'n a brunette riding in an elevator when it stops on the 6th floor and a man gets on. Well, they notice that he has some dandruff on his shoulder but politely decline to say anything until the man leaves two floors later. The brunette then turns to the blonde 'n says, "someone needs to give that poor guy some Head 'n Shoulders." To which the blonde replies, "How do you give shoulders?"