Overriding parts of existing json files with a mod?

Short version: Anyone care to teach a man to fish make json-patching mods?
I have a personal set of tweaks to one of the json’s that I’d like to package and share as a trial run for a more elaborate mod I’m thinking of putting together, but I’m not sure how to do it, or if its even possible. How does one go about taking some mutation.json tinkering I did, deleting and inserting lines here and there in several different mutations, and package that as a mod?

Long Version with details:
While playing a rat character, I discovered that Saprovore (the one that lets you eat rotten stuff) was both not assigned to the rat category, and was inexplicably linked to carnivore. Rats, like a lot of pure scavengers, are omnivorous living trash cans, so neither of those things makes sense. I’m normally a just-go-with-it guy on that sort of realism break/odd game decision for the sake of challenge, though, so I just shrugged at first. A few days, however, of my rat character barely scrounging enough food together to keep up with Rapid Metabolism next door to two grocery stores full of stale bread, moldy dairy products, and rotten fruit and veggies, and not able to eat it with or without Saprovore was a bit much. Both the old-school masochistic min-maxing-within-spirit-of-the-rules gamer and the my-character-uses-his-shield-as-a-blunt-weapon" tabletop RP’er in me agreed that it was entirely reasonable that my rat be able to eat slightly-past-sell-by-date food of any sort, like the mouse I’ve been trying to get out of my pantry for ages. : |

So I fixed it. What I ended up doing was going into the mutation json and stripping out all ““cancels” :” and "“prereqs” between saprovore and the carnivore/herbivore chain, making saprovore a stand-alone mutation that lets you eat rotten stuff regardless of whatever else you can or can’t eat, and then added MUTCAT_RAT to Saprovore. Been running it that way for a few days on a Genetically Unstable, Radioactive, post-threshold Rat character with a purifier and mutigen addiction who frequents toxic waste disposal sites and haven’t had any trouble with it.

Now I just need to know how to make something that inserts into or overrides the existing .json those changes. I sort of know what I’m doing with c–(java to those who missed C++) and lua, but go slow since I’m really trying to understand what I’m doing here rather than just do this one thing.

On a side note: This vastly improves the balance on Rat without being “easy mode”. They’re still high maintenance as hell- its just that this one tweak makes their threshold mutations a sustainable, useful, type of high maintenance instead of a death sentence in the guise of positive mutations. Given that saprovore’s name is so similar to sapiovore(you can eat people, which makes sense as a non-rat, carnivore-prereq mutation…), and that saprovore is needed as a prerequisite to the rat’s Intestinal Fortitude, I honestly can’t help but wonder if I’m just undoing some sort of mixup made during a long coding session… been there, done that. : )

I believe you just make a mod folder, drop you entire .json file with everything ,not just the modifications, into to it and drop it as a mod.