You can download a ZIP file which has both instructions, and a free macro file called "addtones". This macro file originally comes from http://www.mandarintools.com, but I've digitally signed this one, so that it can be used with "High Security" setting in Word.
( A "macro" file is a small set of instuctions, that you can run with a single click, inside of Word, etc. (This might also work in Excel, but I haven't tried it) )
I also included (as a technical reference), how to digitally sign files, if anyone is so inclined. It's not needed, if you don't want to do this, and can be ignored