Download and install the Child Theme
WordPress considers a Child Theme as an entirely separate theme, so the process of installing is similar to installing a Parent Theme. We recommend you follow these steps to get a Child Theme up and running.
The significant part of this process is that you don’t have to worry about the next session of the theme’s updates. If you add customizations in the Child Theme, all the changes you made will be automatically saved.
Adding custom CSS styles
There are two different ways to add custom CSS to your Child theme — use an FTP client or the WordPress Dashboard. If the first method requires connecting to your site via FTP and editing the style.css file, the second one is much easier because you have to go to your WordPress Dashboard site under Appearance → Editor and select style.css from the right side and start adding your CSS. Simple as that.
Editing the functions.php file
If most files in your Child Theme overwrite the parent theme’s files (like style.css does, for instance), the functions.php file is pretty different. Instead of overwriting the parent theme’s functions.php file, you can load it in addition to it. Basically, your child theme’s functions.php file is loaded right before the parent theme’s functions.php file. You have to use a functions.php file only if you want to replace or modify a function from the Parent theme.
Editing or adding a new template file
Beyond CSS and Functions changes, we let you do structural changes to your theme by changing the PHP template files. In most scenarios, we recommend you create a copy of the template files you want to change from the parent theme and modify the copied files. This way, you make sure you’re on safe ground.
For example, if you want to modify the content-single.php template, copy and paste this file to your Child Theme folder and make the changes you want there.