Modifying TrueType or Adobe Type 1 fonts with ResEdit or similar development tools such as Resourcer is not a trivial task and is not for the faint of heart. We recommend you either obtain a tool such as Fontographer, or request a font name change be made by Adobe, or perhaps work with a consultant or a knowledgable programmer to make the appropriate name changes to the font, so that the "new" font gets downloaded. The reason for the name change is it would make the Font appear to the printer to be unique, so it would be downloaded and used. If the Font in question isn't a "ROM" Font, then either the old Font is stored in the printer's hard drive or in the printer's RAM, at which point is is merely a matter to delete the Font from those locations, and
download this other Font.