Quote - You are not "replacing" anything.

You are "adding" (+) the hair as a parented prop (object) to a figure's head.

cheers,
dr geep
;=]

Thank you, Dr. Geep, however, while I fully understand the concept, the program does not give me the option to parent the hair prop to the figure.  That is, the prop does not show up on the list of parentable items and it is for that reason that I sought an alternative approach, ergo, "replace part."