Go through these steps if you want to completely uninstall and delete your BindTuning theme.
Open your admin area and from the left menu click on "Themes".
You should be able to find your theme there. Go through your list of themes available and set one as your current theme.
Now you are ready to go.
Uninstalling the theme
Warning: Uninstalling the theme will permanently delete the theme from your website and all its files.
Uninstalling a BindTuning theme from Orchard website is pretty simple and straightforward.
Still inside your Themes area, click on "Uninstall". If a message comes through saying "Are you sure you want to remove this element?", click "Ok".
That's it. Your theme is now uninstalled and deleted from your website.