Passing modified ASP.net MVC model to AngularJS controller

I'm new to Angular and relatively new to ASP.NET MVC. I've successfully managed to pass my server model to my AngularJS controller. However, I want to be able to edit my model before passing it to the AngularJS controller.

How would I go about to achieve this? Any help is greatly appreciated!

My view:

...
            @if (Model != null)
            {
            <table class="table">
                @for (var index = 0; index < Model.Fields.Count; index++)
                {
                    <tr>
                        <td>@Html.DisplayTextFor(m => Model.Fields[index].Title)</td>
                        <td>@Html.EditorFor(m => Model.Fields[index].Value)</td>
                    </tr>
                }
            </table>
            } 
...
<form class="form-horizontal" role="form" ng-submit="posta(@System.Web.Helpers.Json.Encode(Model))">
    <div>
        <ul>
            <li ng-repeat="article in articles">
                {{ article.Article.itemNumber | uppercase }} - {{ article.Article.itemDescription | lowercase }}
            </li>
        </ul>
    </div>

    <div class="form-group">
        <div style="padding-left:110px">
            <input type="submit" value="OK" class="btn btn-primary" />
        </div>
    </div>
</form>

Controller:

var myApp = angular.module("ArticleApp", []);
myApp.controller("articleController", function ($scope) {
$scope.articles = [
  {
      Article: {
          itemNumber: '1234',
          itemDescription: 'Test'
      }
  },
    {
        Article: {
            itemNumber: '5678',
            itemDescription: 'Test2'
        }
    }
];

$scope.addRow = function () {
    $scope.articles.push({
        Article: {
            itemNumber: '2222',
            itemDescription: 'asdasd'
        }
    });

};

$scope.posta = function (model) { //Model does not contain changes :(

    var m = $scope.articles;

}