Remove unused themes because it is protecting your WordPress website from vulnerabilities.
1. Login to your WordPress admin dashboard.
2. Below the dashboard menu box, hover your mouse on “Appearance” and so press on “Themes”.
3. Hover your mouse on a theme that isn’t active and unused otherwise you want to remove that theme.. it’ll show you the choice “Theme Details”. Click it.
4. A simple window will open. At the bottom area, on the right side of the window, you’ll be able to see the “Delete” possibility. Click it!
5. A confirmation window can open. Click “OK” to remove your theme.
The theme is successfully removed!