would be a very hard task if you don't really know where to even start, just saying. you would really have to find a functional source grabber (I say functional because most try to use jpexs which just fucks with a lot of the code and causes more errors than even the proper source will cause you when pasting into a flash project) such as as3 sorcerer and download the source and well get another client source for as3 which is easiest method and just replace the src file with the contents you grab from as3 sorcerer and then you would probably have to use jpexs to get the actual assets like sprite sheets and xmls and whatever else as3 sorcerer may not read, get those all together and throw them in as well, and from my experience, lots and lots of errors happen after this which usually unmotivates someone like me into quitting at that moment haha