Oral exams are all about demonstrating what you know capably. A successful presentation also depends on your articulateness, body language and posture, clarity of expression, and social skills. Examiners are not your opponents. Instead, they are partners in a process you have decided to undergo. Your job is to present your knowledge appropriately, reflect on it, and be able to discuss it. You are expected to be able to provide an overview and to focus on individual aspects.
Here are a few tips that can help you with oral exams:
You can also see the Self-care section for tips and tricks for dealing with stress and exam anxiety.