If you used our software installer then it's very easy. All you need to do is click on Actions > Download Backup. Our system will automatically create a live backup of your website and you will be able to download it instantly.
If you did not use our installer then you will need to go to cPanel > File Manager > yourdomain and compress all of your files. If you also used databases, go to cPanel > phpMyAdmin and you can export your database from there.