Oneshef

I noticed that, when using any other language, the "Mod Options..." button will not change to that language. If I wanted to modify that button (and any other string Forge includes), how would I do it? I tried modifying the .lang file in the JAR, but it just resets itself after I open the game no matter what. I tried deleting the META-INF folder, but somehow it still resets itself. If it helps, I'm on 1.12.2.