Illusion and disguise. That is how you will fool the Black Dragonflight, and gain what you seek.
Though I could teach you something of the skills of deception, you need the help of a master.
I know of one who could do this. In the Western Plaguelands, you will find Myranda the Hag, once a master illusionist of Lordaeron. She has helped us in the past, and if she believes the cause worthy, she may help you.