1. Download phpagi (Just google it)
2. Use it to connect to the Manager interface
3. Use it to issue:
phpagi actually has a method in the manager class to do this. Just use the "Command" function with a parameter of "reload"
This way you dont't have to change any users. And you are mor secure, since you can restrict the manager interface to only listen on localhost.
$socket = fsockopen("192.168.0.245","5038", $errno, $errstr, $timeout);
fputs($socket, "Action: Login\r\n");
fputs($socket, "UserName: admin\r\n");
fputs($socket, "Secret: blabla\r\n\r\n");
fputs($socket, "Action: Command\r\n");
fputs($socket, "Command: reload\r\n\r\n");