Unzip file you downloaded into your Cinema 4D's plug-ins folder.
Windows: c:\Users\%USERNAME%\AppData\Roaming\MAXON\CINEMA 4D (version whatever)\plugins\
Mac: Applications > Maxon > Cinema 4D (version whatever) > plugins\
Now restart the application.
Unpack the installation files to disk.
Start the Cinema 4D program. Go to Edit > Preferences > Plugins.
Add the folder with the unpacked plugin files to the list.
Go to the Plugins (Extensions) menu to run the plugin.
To make sure everything went fine you can check the Console in Cinema 4D. Use the Script > Console... menu to open the Console. You should find a message showing that the plug-in has been loaded.