can someone tell me how to get this cd or addon?. what needs to be done?

You need to wait till they actually release it. It is going to be called DCS:Black Shark. It might come out at the end of this year.....maybe.

After they have got rid of all the bugs that plague lockon and flaming cliffs prob....It does look rathergreat though...so fingers crossed and demos ready before the parting of the cash can take place lol!