You'll need this>>
Flasm: http://flasm.sourceforge.net/
sothink: http://isohunt.com/download/69837813/sothink.torrent
notepad++: http://notepad-plus.sourceforge.net/uk/site.htm
Follow the steps by steps decompile swf flash application know its bytcode edit and change them.. a very nice tutorial.
http://www.youtube.com/watch?v=jrhKRcC1Mb0
