Why do you want to recompile our code ? You dont need to for a mutator. With a mutator you extend from our classes but really only compile the mutator and not the renx files. Like the renx files are extending the UDK files but we never had to recompile them. You only need to decompile our code to see what it looks like and what you could change in your extensions/mutators but you dont have to and shouldnt recompile it.