Actually, if all you care about is the change fee, it’s pretty straightforward. Just search the fare rules for the currency code (e.g., USD). There may be a few surcharges at the top of the rules, but when you get to the changes section, it’ll be obvious.

What can be difficult is knowing what the appropriate fare will be after a change. (e.g., is the entire trip re-priced, or just the leg in question?)

Actually, in this particular case, it’s not lawyers to blame, but rather automation. The fare rule text is generated automatically based upon the set of rules that the auto-pricing system will use if a change is actually made. They’re not really meant to be read by humans.