There probably isn’t a simple button you can push (unless there’s a special one the theme developer created), but it can most likely be done via some basic theme tweaking.
First, make a child theme. There are lots of tutorials about how to do that.
Second, modify the child theme. Two options for this:
- hide the message via CSS: Find the CSS class for some enclosing HTML tag (there are several ways to determine that), and hide it via a CSS
display:none. One drawback is that there’s a risk Google might be unhappy with the page hiding things. - customize the footer: Copy
footer.phpfrom the parent theme to the child theme. Edit the copy and remove the text you don’t want, plus perhaps any enclosing now-empty HTML tags. One drawback is that if you later install an updated version of the parent theme, the child theme will still be using a modified version of the old footer.
Also, the generic WordPress themes have a similar footer message, which many people want to remove. So a web search for ‘remove proudly powered by WordPress’ should find lots of tutorials. Your situation is probably almost the same.