Hello, I am an old lady and I am trying to put the plugin in the calibre 2.63 64 bit by David Koval (that is what it says at the bottom left of the screen. I have the plug in downloaded it to my extra hard drive and I unzipped it.

I can delete that and redownload. I understand I messed up. I tried downloading it to program files and calibre plugins, but the computer told me I couldn't. So where do I download it?
But my issue is I cannot find a button or link on the preference like it says here "In Calibre choose Preferences->Plugins. Click the Load plugin from file button (Calibre 0.8.6 or later) or Add new plugin button (Calibre 0.8.5 or earlier) to browse to your plugin .zip file and click OK." All I got on the user plugins page is a link to this plugin homepage. and a greyed out button that says customize plugin and 2 buttons that say install and ok. I have NO plugins installed so.... Can someone please help me?
Thank you.