mass replacing font

Is there any way to do a project replace on a font style?
My novel uses TNR for everything but text messages that appear throughout the 88,000 words. I have used Helvetica (and Format/Formatting/Preserve Formatting so that the compile to Word works) for the texts. I just discovered that the Helvetica font is not supported in several PC OSs, which is problematic. (For instance, my editor doesn’t see the Helvetica.)

I now know, no thanks to Microsoft, the five serif and five sans serif fonts that work across every Mac and PC OS since 2006 (cross-reference attached), but now I need to change all the Helvetica to Arial. Help!!
Font crossreference.doc (218 KB)