Park in main forest car park and walk 1-2km (10-20 mins brisk walking) west, or until you feel comfortable. If you plan to linger, it is best to walk to the two large sand dunes (one high and one wide) as the coastal path is inland at this point. People do occasionally walk/cycle past but they are generally not phased by naked people.
Information provided for guidance only. All activity at your own risk.