After submission, spend a little time exploring three aspects of your examiners.
First: read two or three of their most recent publications. You don’t need to become an expert in what they do, but being sure of their topics, methods and research can help in the viva.
Second: Google them! Take a look at their staff page and the interests they declare. How familiar are these topics to you? Is there anything you can practically do to find out a little more? Again, you don’t need to be an expert. This just builds the picture in your mind of who you’re meeting.
Third: ask your supervisors, friends and colleagues about your examiners to know a little of their reputations. Who are they? What are they like? What are they known for?
Learning about recent publications and interests can help you practically engage with your examiners on the day of your viva. It could be this is not a big task for you – over the course of your PhD you could have already learned a lot about their work.
Learning of their reputations can help with how you feel about your viva. Knowing that these are real people really helps with your confidence at meeting to discuss your work with them.