You must be in the Admin area.

• Under the Articles menu, open the Categories tab.
• Filter the list by selecting a category with child categories you want to reorder. Note: You can only re-order one level in a time.
• Click the button with three dots [...] in the top right corner.
• Choose Reorder from the popup menu.
• Rearrange the categories by dragging and dropping them in the results list.
• Click Save.