Thanks for the comments--there is one I do not understand.
You seem to have tried to change a method's bytecodes and have it take effect. What exactly did you try? There is a way to do this, using the methods in mirror.sm to create new methods (based on info from old ones), and then do a one-way become (called *Define* (stars are wildcards)) in mirror.sm. I can send you a short program that does it, if you are interested.