You can find file plugins.css in royal/css/plugins.css and open it, then copy all your css code and minify it via https://www.cleancss.com/css-minify/ or through another minifier, then copy minified css and just add it instead of previous one into file and save.
For file settings.css please try to do the same way, and I don’t know where did you get that file because of there is no file with the same name in our theme. But if you want to minify it, just do the same way as in previous.
