You can restore the backup from the cPanel as follows:
1. Log in into cPanel.
2. Under the tab file, you can see the label backups.
3. Click on backups.
4. Select the backup file which you want to restore.
Note: You cannot use a full backup to restore your site via the cPanel interface. The file must be downloaded and decompressed prior to restoration. Once the file has been decompressed, you will be able to upload and restore individual pieces of your website contained within the full backup.