1. Update the Arnold theme… without affecting the Arnold child theme currently used for my site. How can I do this?
2. I want to prepare a new version of my site with a new child theme that uses the demo data and not have it live yet (like a staging environment) while my current website remains live. How can I generate/install a new child theme to set up for this?
2. a)Make sure you have installed the Arnold theme, the theme fold name can not be chagned, it is should be arnold(default).
b) The way of Installing child theme is same as normal theme, in Appearance > Theme, Add new, choose “arnold-child.zip”(unzip the arnold-mian.zip, you will find it) to install.