The short (painful) answer is to start with the default patch, change parameters one at a time, and look through the hex dumps to see what changed in the output. If you have a list of parameters that you care about editing most, start with those, because then you get something up and running quickly that has partial support. Then you can add more ...
Don't bother reverse engineering.
Just look at the end of your owners manual.
It's all there.
That manual is a must-have if you plan on writing an editor. Google for "cs1x owners manual". I just did it, and this was the first that popped up:
Note: I don't own a cs1x, but I'...