Redefine your audience generally means changing how you see your audience. Instead of seeing them as lecturers who are evaluating you, maybe you can convince yourself that they are all fellow students who are in queue to present after you. They are all equally nervous so there is no reason why you should be too.
Or perceive them as long lost friends that you haven’t seen for 10 years. This way you can maintain eye contact trying to figure out where you have seen him before. To the audiences, they will see a very friendly and personal presentation.
Do not try to convince yourself that they are babies in diapers or that nobody is around as suggested by some books. It is very hard to convince yourself that no one is around when you are actually speaking to them.