Here is a simpler approach, we recommend our customers to use.
- Zip the files.
- Upload the zipped/compressed file via FTP.
- Login to cPanel account at http://{ip}/cpanel or http://yoursite.com/cpanel.
- Click "File Manager" under Files column.
- Select appropriate directory to open.
- Find your file and click on its name.
- Click "Extract" button.
It is recommended that you upload and uncompress the file in an empty directory/folder to avoid it from messing up with your existing files.