Use the Switch Join Order tool to reverse the way in which elements join together. 
-  Open a view that displays the elements to be joined. 
- Click Modify tab Geometry panel Geometry panel Join drop-down Join drop-down Switch Join Order. Switch Join Order.
- If you want to switch the join order of multiple elements with a common element, select Multiple Switch on the Options Bar. 
- Select one element. 
- Select another element that joins with the first element. If you are using the Multiple Switch option, continue to select elements that intersect the first element.  
- To exit the tool, click Modify or press Esc.