How do I use terminal in Linux to find and install the Flash Player plug-in?

http://ift.tt/1iZHv9S

I am new to Linux and am running the ElementaryOS (an XP refugee). I need to load the Adobe Flash Player so I can do some things with my browser Firefox 28 and it says I need to go to the terminal and find the browser plugin folder and load the files there.

I can’t find the browser plugin folder using the terminal app. and if I do I don’t know what to do then.

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