Grading for the All Day Shirt

I would love to make an adjustment to the All Day shirt for a better fit for my body. Ideally, I would use the "large" yoke with the "x-large" body parts. My shoulders are not very broad--at least I'd rather say that than to say that I have slightly too much girth in my torso for my frame. Is there a simple way of making this adjustment? I'm imagining I would probably have to adjust the sleeve cap as well? Grateful for any suggestions. Thanks!