To replace the heading icons on the Celebration style, add the following to the “Extra CSS” field on the “Geeky Stuff’ tab in EasyRecipe Settings

.easyrecipe .ERSIngredients .ERSIngredientsHeader {
  background: url(your ingredients icon url here) no-repeat;
  padding-left:40px;
}

.easyrecipe .ERSInstructions .ERSInstructionsHeader {
  background: url(your instructions icon url here) no-repeat;
  padding-left:40px;
}

.easyrecipe .ERSNotesDiv .ERSNotesHeader {
  background: url(your notes icon url here) no-repeat;
  padding-left:40px;
}

.easyrecipe .ERSNutrition .ERSNutritionHeader {
  background: url(your nutrition icon url here) no-repeat;
  padding-left:40px;
}

 You may have to change the padding value depending on the width of your custom icons;