Help introducing a new puppy to an aggressive dog?

It is your responsibility to make sure that the pup only has good experiences. Maybe your older dog should be an only dog. Try keeping the adult dog on a lead when pup is about and then you have more control. You may have to remove the older dog many times when he begins to aggress. Do it as many times as it takes and he will get fed up of being removed. When he is in the same room and calm make sure you give him treats. Associate a phrase like " be nice" to the calm behaviour and he will learn.