Of course you would be. That's because everything after "make your changes" is supposed to be applied by the Scheme compiler, possibly with assistance or annotations from the programmer (e.g. macro expansion, tail recursion elimination). Doing it manually is the Wrong Way (TM) unless you're in a PL/compilers class.
Did you read the story that this whole discussion is about? Everything after "make your changes" was the procedure that was followed in the story. The final result was a C program that was substantially faster than anything which the Scheme compiler could ever produce.
No Scheme compiler would be likely to do those transformations for you.
