各打五十大板 Give each side fifty strokes. To punish both sides equally, without deciding who is right.
和稀泥 Stir thin mud. To smooth over a dispute, usually without regard to principle.
息事宁人 End the matter and calm the people. To settle a dispute and restore peace.
大事化小，小事化了 Turn big problems into small ones, and small problems into nothing.