Transpose words using the Replace feature
It's especially useful when you'd like to switch a name from last name first to first name first.
For example, type (Smith), (John) in the Find What box and type \2 \1 in the Replace With box. Select the Use Wildcards check box:
Click Find Next, and then click Replace. Word finds Smith, John and replaces it with John Smith. Placing the comma outside the parentheses ensures that it's eliminated when the replacement text is inserted.
See also this tip in French: Transposer des mots à l'aide de la fonction Remplacer.