Hi there,
Thanks for writing in! If you haven’t done any customizations directly to your X theme templates (i.e. changing template files/ add or remove codes), you can safely setup a child theme as mentioned on our guide here (https://community.theme.co/kb/how-to-setup-child-themes/).
If you have done any customizations, you need to locate the template files that you have done changes and then move them to your child theme’s respective location.
Hope that’s clear.