Changing options after plugin used

Changing options after plugin used

So I want my plugin to be able to change it's options AFTER the plugin has been used on an element. Something like this:
$("elem").plugin.options.someOption="something"

This is how my plugin is set up:
  1.     $.fn.fileSelect=function(options,callback){
            var defaults={
                dir     : '/',
                exts    : 'php',
                phpFile : 'get_files.php'
            }; 
           
            return this.each(function(){
                var opts=$.extend({}, defaults, options);
                //plugin code
            });
        };











I thought I could do $("elem").fileselect.opts.dir="/", but opts comes up as a non-existent variable.