How to change excel legend order?
Source How to Change the Order of the Legend in an Excel Chart
Right-click on one of the names listed on your legend.
Click on the "Select Data" option from the list that appears.
Click on the entry you want to move in the "Legend Entries (Series)" box.
Click the "Up" or "Down" arrows in the box to change the position of the legend. Click "OK" when finished to save your changes.