My bad. I did not adopt the parent-child practice for my multisite which is using Edu-Clean theme.
Nevertheless, guess it's never too late to adopt the child-theme thingy.
Problem is I've made quite a bit of customization with the original (parent) theme. Anyway, would like to confirm 2 things here :
1. So to adopt the parent-child theme, all I need to do is to copy the entire edu-clean folder to /wp-content/ (ie. /wp-content/edu-clean) AND also the child theme (edu-clean/themes/edu-clean-child) to wp-content as /wp-content/edu-clean-child ... so the wp-content includes 2 theme folders - edu-clean and edu-clean-child? Then it is the child theme that we activate in the dashboard. Is this correct?
2. Since I've already made customization to the parent theme currently, I'd to back-track to identify the changes I've made and repeat the customization (coding edit) on the child theme?
Best Regards, William