I would reiterate what has been said on here, all good advice. The examiner is not looking for inch perfect flying. The impression I got was that the examiner was more interested in common sense/airmanship than anything else. On my diversion I got temporarily unsure of position but didnt give up and I managed to rectify the situation. I also nearly undershot my PFL (my least favourite manoeuvre!) but was able to explain why so got away with it.
Your instructor will have taught you to fly to a much higher standard than is required for the skills test.
On the oral part of the exam if you dont know the answer admit it. The response 'I dont know but I can find the answer in the POH/ ask an instructor' etc is the next best thing to the correct answer. Above all do NOT bullsh*t.
Best of Luck Ian and Cricket