You don't necessarily need a Bannerlord mod to modify these two values. This can be done by creating an external application that does the modifying once the game starts. It would look up the folder location of M&B Bannerlord, open the file, modify the values and save it.
I'd suggest:
1. If you plan to do any further development on your mod in the future, find a video that explains how you can create and start a Bannerlord mod. This includes how you can use your built C# code to run when Bannerlord starts;
2. Write a piece of code for getting the location of M&B Bannerlord folder. This could be by using some fancy library, a built-in library provided by the modding tools by TW / looking this up when the game has started by looking up the running process / etc. (there are so many ways to do this)
3. Write a piece of code for selecting the file to access;
4. Write a piece of code for looking up the row you need to modify;
5. Write a piece of code to replace the values with the values you want on the selected row;
4. Write a piece of code for saving the file.
Once you build the project you can go to the "bin" folder and find the .DLL there.
Most developers suck at remembering how things work and one thing they're good at is doing research online. There are so many videos that will explain everything you need to know, just give yourself time and don't expect to do this in a day. Usually you will run into roadblocks but that's when you learn the most. Good luck!