Login to your Control Panel at www.yourdomain.com/cpanel using your cPanel username and password. Click¬†'File Manager' which is located under the 'Site¬†Management' menu, this will bring up the 'File Manager Directory Selection' box where you select which directory you would like to open. This will bring up a list of all the files contained within this directory. Right-click on a file to bring up the management menu and click on 'Change Permissions'. Make the necessary change and once again click 'Change Permissions'.