the location of the php.ini varies between different servers. In addition, some hosting providers don't provide access to the php.ini.
You can try increasing the upload size in php using the following:
ini_set("post_max_size", "30M");
ini_set("upload_max_filesize", "30M");
ini_set("memory_limit", -1 );
But some servers don't allow to overwrite the values in php and required to use the php.ini.
If the above did not work (you can test it by using phpinfo() after), contact your hosting to help you increase the upload size.