Conversion of configuration between Windows & OS X systems

I am struggling with the configuration of items required to apply chord symbols and suitable fonts within my computer.
In Chapter 2 of the initial 9.2 handbook there was clarity in the methodology by writing for a windows system with the Mac
requirement in brackets (Linus & Ubuntu are not included). In Chapter 9 it becomes increasingly clear that the alternate systems require separate instruction. What can be done in the future ????
For the present, referring to an excellent post called "Creating a Lead Sheet with Musescore 1.0" .... I have no idea where to
place the three files obtained from unzipping the attachment, as there is no filing system attached to the MuseScore. app.
on my Mac (using OS 10.5.2 Leopard) There are no files within my system with extensions such as MSCZ or MSCX either .... can anyone help????
I suspect I have to use a terminal session, but I'm not sure what to type.