How to install plugins??

Sorry if I'm mssing the obvious, but on both the main plugins page and on the Add And Remove Courtesy Accidentals (the plugin I'm after), I see no directions for installing them.

I opened the Plugin Manager within MS, but I'm still not finding anything.

Thanks.

UPDATE: Okay, I figured it out: zip them into the appropriate folder. All is good. (It would be nice, though, to have those instructions for non-computer geeks to know what to do. Thanks)