Ask him for the guideline of the project and cc his boss

As a matter of fact, because of he is the team lead, and you are reporting to him. You have to do what he is asking you to do. Of course, because of you cannot get any guideline from him, if the project fails, it shouldn't cause you too much trouble. The bottom line is, let the manager knows that you are doing work as he requested without any guideline from him.