Hello, @TFS,
Unfortunately, there is no such option in our theme to change that icon, but you can change it using Custom CSS.
First of all, you will find all our theme icons here: https://xstore.8theme.com/xstore-icons/
You have to use the below given CSS code under XStore >> Theme Settings >> Theme Custom CSS >> Global CSS and you can change the item code as per your requirements.
.single-product .stock.step-2::before { content: '\e92a' !important; }
See the image for a better reference in the private content area.
Regards 8Themes Team.
