I want to update a line item on an existing order. I want to change the color or size of a line item in an order. According to my research, Shopify does not allow customers to update existing line items. I thought about setting the quantity zero of a lineItem to remove it from an order, and then adding a new variant. However, I was unable to set the quantity of a line item to zero. Do you guys have any idea how can I remove the lineItem or update the existing lineItem?