If you're ready it will be a walk in the park. Unfortunately the pressure of it being a test changes that. Know your checklists inside out and back to front to take some pressure off the actual flying and try to be as 'laid back' as possible. After all there is no need to be concerned, your instructor knows you are ready for it and s/he has nothing to gain by throwing you into a test if you are lacking in the appropriate skills.
Take your time, trim to allow yourself time to do all your tasks at leisure and keep a very good look out. It's good airmanship but more to the point, loads of brownie points in a skills test.
Good luck (although that doesn't really come into it)
