Timothy, your ability to modify the PHP setup will depend on what your hosting provider allows.
If you don’t have access to it, you might be able to ask your hosting provider or server administrator to remove the readfile function from the disabled list.
What you posted above is only a part of your PHP configuration, probably from your account-level php.ini file. To get the whole picture, you can upload a phpinfo file to your server and call it up with a web browser. See this: http://php.net/manual/en/function.phpinfo.php
Use the code listed in the example to create your phpinfo.php file, upload to your server and call it up: http://www.yoursite.com/phpinfo.php or whatever path you place it under.