Working with Instances, adding an event and Embedding a video!

Hello guys,

I am new here and a novice in flash.
I have been going through tutorials for a couple of days.
I was trying to make a CBT. I have some video recordings for the same.
My requirement is to wrap the entire CBT in a Flash based window.
I downloaded a free template from internet and am trying to work with the same.
But I am unable to understand it completely. I am attaching the template here.
Could anyone explain how it works?
The template uses multiple instances of library items and hence when i add a text or make any changes, it reflects on all instances instead of the particular instance on which I need it.
Also I want to add events on buttons so that my videos are played when one clicks on the dropdown menu.

Any help would be greatly appreciated.
Thanks in advance :)