The fact that you're trying to excise a message saying "this has been stolen" suggests that it has, in fact, been stolen. If that's the case, then your question really isn't appropriate here.
If it were just a SWF that someone put out there without any stated restrictions, that would be one thing. But if they've taken some steps to prevent you from downloading it and running it locally -- even if these steps can be easily circumvented -- that should make it clear that the terms under which they're licensing you to use the game do not allow for you to do it that way.