I cannot figure out how to use a Model Changer!

[Lolmodelchanger]

I use a IMac G4, and am trying to use the Model Changers in these forums to switch my items (Specifically the armor/weapons.) I'm here now because I cannot seem to figure out what exactly I need to do. Do I download a Armor Changer, throw it in a certain file and turn World of Warcraft Launcher up?

[Lolmodelchanger]

I've read multiple guides on opening Hex and other item changers, yet when I download said things, nothing happens. I assume this is because they were made in mind for a PC. Is there anyway to bypass that?