RE: Changing training time, how should meal plan change?
You want another energy source if you are leaving out carbs in some meals, i.e. healthy fats and EFAs.
Reduce the carbs you are having at breakfast, PWO and PPWO and whatever you reduce them by, add them before training.
I.e. if you were having 45 grams for breakfast, 45 grams for PWO and 45 grams for PPWO = 135.
135 / 4 = ~33 grams of carbs in each meal.