Hello,
Sorry to say but as you know the Checkout comes from WooCommerce. So, for any sort of disabling of Steps, we would suggest you to contact the WooCommerce Support in this regard.
Further, Sorry to say but your WoodMart Theme and WoodMart Core plugin isn’t updated to the latest version. The latest version of the Theme running is 7.0.3 and the Core version running is 1.0.35.
So, please try to update your WoodMart theme and Core plugin to the latest version too by following the given Theme’s Documentation link: https://xtemos.com/docs-topic/update-the-theme/.
Best Regards