Its not that hard really. I ran into the issue with a website I was making and I found the same issue with tutorials.
What I did was this, but be warned it is tricky to follow at first because its basically reverse engineering but it does work and it gets easier with practice.
I went to thepiratebay.com and got SWFCatcher via torrent. Install that, and fire up...ugh...internet explorer.
Go to templatemonster.com and pull up the flash templates. Find one that has the volume adjustment and/or the on/off feature. Most only have mute its rare to find a slider. Once you find it, open the demo and while its playing right click anywhere on the page and choose the swf think capture option. Save the file anywhere on your computer.
Go to the file and right click it and choose "convert to fla". Follow all suggested prompts.
You can now open it as a project in your ide of choice and it will be 100% intake and dissected, and you can locate the things you need and see how they are done and work.