how to update json data in an external file using angularjs services

i have written a small piece of code which will add the elements into the json array. i dont know how to update that json array to an external file using angularjs services, and also tell me how to do delete and update operations. can anyone help me? here is my code.

//services.js
angular.module('Services', ['ngResource']).
factory('Events', function($resource){
    return $resource('/Event/:File.json', {}, {
        query: {method:'GET', params:{File:'Json'}, isArray:false},
        update: {method:'PUT', params:{File:'Json'}}
    });
});

 //controller.js
function MonthCtrl($scope, Events) {
$scope.data=Events.query();

//Some operations to display the data in view

$scope.createEvent = function($event) {
    var eventname = document.getElementById('eventname').value;
    var startdate = document.getElementById('starttime').value;
    var enddate = document.getElementById('endtime').value;
    var description = document.getElementById('description').value;
    var eventtype = document.getElementById('type').value;

    document.getElementById('eventname').value = '';
    document.getElementById('starttime').value = '';
    document.getElementById('endtime').value ='';
    document.getElementById('description').value = '';
    document.getElementById('type').value = '';

    $scope.data.Dec2012.push({name:eventname,start:startdate,end:enddate,type:eventtype});
    Events.update($scope.data);
    $('#popup').css("display","none");
    $event.stopPropagation();
}

Thank you