Swapping child theme but keeping content

Dear WPMUDEV team

I've searched for an answer to my question but cannot find it, or at least have so far failed to.

If anyone can help with the following it would be most appreciated!

In Upfront, is it possible to change the Spirit theme to the Fixer theme and keep all of my custom content? Text, photos, blog posts etc.

I'm thinking that the Fixer theme might be a better starting point for taking the site forward an I don't want to start from scratch by changing the theme.

Thanks for any advice you can offer, apologies for the question.