1. Login to Sniffie.
2. Navigate to price matrix.
3. At the top right, click on the gear icon to open price matrix settings menu
4. Select the "Edit column order" option in the menu. It's the one with the edit icon, not any with the checkboxes.
5. A modal opens. You can now drag and drop the stores in the desired order as you wish. The top element appears leftmost in the price matrix.