If you've been working with Backdrop for a while, you'll notice that sometimes, a particular module, theme, layout template (or sometimes even Backdrop core) doesn't quite work right - or - perhaps it just doesn't quite work the way you'd like it to for your particular project.
Fortunately, this is the world of open-source, and you are most likely not the first person to have this concern. Your first line of attack should always be to search the issue queue for the project and see if someone else has already fixed this problem for you (or added the new feature). Quite often, you'll find that they have, and there will be a Pull Request (PR) linked from the issue containing the necessary changes to the code.
Once an issue has a PR on GitHub, it's easy to create a patch for your own site by adding
.patch to the end of the URL.