First you must unzip the downloaded file which will reveal a set of folders labeled R15, R16 and R17. These contain the plugin version that matches the namesake version of Cinema 4D.
To install, open the folder that matches the version of Cinema you are installing into and drag the plugin folder to your Cinema 4D plugins folder. You can find this by going to your Preferences from within Cinema and clicking the “Open Folder” button at the bottom of the preferences window.
Before you can transfer to another machine you must deactivate the plugin on the current computer. You do this by clicking the “Unregister ‘Plugin name'” command found in the Plugins Menu within Cinema 4D before closing Cinema 4D.