I want to breathe under water, but I dont want to use a Snorkle or any Scuba equipment. (that is how your question sounds to me)

I think your question is not being responded to because you are asking to do something (edit flash) without using the tool (Adobe Flash).

Unless the original designer gave you the original .FLA files, you will not be able to open and edit .SWFs that are viewable on the website. If you dont have any experience using flash, you may encounter issues editing the source files. Adobe gives a 30day free trial if you want to give it a shot.

If you inherited a website that you can not maintain, I would suggest creating one you can maintain. There are several sites available for non-designers.
http://website.1and1.com/