some "brute force" strategies to help someone change BEFORE into AFTER, while minimizing the amount of 'hand editing' necessary.

Oh, you only want to minimize the hand-editing necessary, not eliminate it. Yes, that's a much easier problem. Copy and paste will help for starters. It's also pretty easy to write tools that will do things like capitalize the first letter of every sentence, so that you don't have to fuss with that when you rearrange sentence parts so that the first letter is not the first letter anymore. Using a full-featured text editor (e.g., Emacs) will help considerably too, since you can do things like bind a keystroke to highlight forward to the next punctuation mark and cut or copy the result to the clipboard. (Then all you have to do is go paste it...) It's actually pretty easy to get the computer to do a lot of your editing work for you -- as long as it doesn't have to decide what editing to do.