If a product is already added to the cart, it is possible to edit its modifiers, like in the example below.
To edit modifiers on a product in the cart:
- Select the product in the cart,
- tap 'EDIT',
- scroll down to the bottom of the page and select the right modifier for this product,
- tap 'SAVE' on the top left corner of the window.
Note: Once a product has been saved in open order, it is not going to be possible to change modifiers.