While it is essential to keep WordPress and parent theme up-to-date, it is not necessary to keep your active child theme up-to-date – especially if you have customized it.
Replacing a child theme with a newer version will overwrite any customizations to files like functions.php and style.css. If you would still like to update the child theme to its latest version,
- Take a full backup of your site or at least that of the theme
- Make a note of all the custom theme changes and re-apply them manually after replacing with the new version. Using a filediff software like WinMerge or an online tool like https://www.diffchecker.com/ can be handy to compare the code in theme files
Note: This does not apply to Hello Pro v2 as it will not overwrite your existing Hello Pro v1 theme. It will install as a new theme that you can switch to. You can preview the theme on your site before activating it. Always create a backup before making any theme changes just in case.