After Version 2.2, the script comes with update section where you only need to upload the update zipped file from admin panel (No FTP no CPanel) .. just upload the update folder and everything will be Ok.
Manual Update
To update manually, unzip the update folder and move its content to your server, replace the existed files with new ones.
If there is Database Changes you will find db.sql file, copy its content, paste and execute it in your PHPMyAdmin SQL.