Assets within a folder can be reordered as needed.
Select a folder by hovering over the asset name and clicking on the arrow that appears to the right of the asset name. The contents of that folder will display on the right hand side of the page, ordered alphabetically by their system name.
Click on the heading of the third column titled Order. This will display the items in ascending numerical order. If clicked again, the order will appear in descending numerical order.
To move an item, hover your mouse over the item and then drag it to the appropriate place.
The order will be automatically applied and changes do not need to be submitted, however, the folder that’s been reordered should be published to reflect the changes on the live site.
If some of the folders or pages aren't visible, they may be set not to be included in the navigation.