Let me show you how to restore WordPress from backup. This will work even if you can’t access WP.
I will show how to do theme and plugins restore in file manager. Also we will restore WordPress database.
You will need access to your cPanel and you will need to have backup files for this to work. Here is how you can backup WordPress:
If you don’t have any backups and your WordPress website has crashed. Try troubleshooting your issues by checking this video:
So you can restore manually any parts of the site as long as you have all the required files backed up. In my example I updated themes file, however you could just swap the whole wp-content folder.