How do you convert games from just a .swf file?

As in, convert a flash game that hasn't been converted for any arcade modification before? I couldn't find the exact information in the pinned topics, and a few members of my forum want to know partly from wanting a decent amount of flash games added, from just the game file itself.

So for example, you'd have [insert link to random game on game's site, or even game you made yourself in flash], and how would you convert that to work with the arcade mods scoring and the like?

[GotWalked]

.swf to .tar is what we're looking for. I'm bumping this thread as well as I'd like to add more games that I cannot find the .tar version of. Thanks

[Stifmeister2]

I think it's very hard without the .fla file.

Maybe use some SWF decompiler...