I realize this is an old post but...
From within the equation editor, click the "Ordered View" icon at the top. Next, uncheck the "Automatic Solve Order" box at the bottom.
Now you can click and drag a row to a new position. Click on the row number once to select the row. Click and hold on the row number to drag to a new position. You can also CTRL-select or Shift-select and move multiple rows at once.
When finished, re-check the "Automatic Solve Order" if you had it checked to begin with and switch back to the "Equation View" if that is your preference.