Adding OAuth2 Authentication to the existing ASP.NET MVC 5 application

We have an ASP.NET MVC 5 app and need to authenticate users via an organization by using the following info:

Redirect Uri, Client Id, Secret Key, token_uri, resource_uri.

There are several tutorials explaining this e.g. How to implement oauth2 server in ASP.NET MVC 5 and WEB API 2 and Create an ASP.NET MVC 5 App with Facebook, Twitter, LinkedIn and Google OAuth2 Sign-on (C#) but most of them use Azure or Web API, but I do not want to use API or Azure. So, how can I implement this OAuth2 Authentication?

Update:

Here is my code using @WiktorZychla's tutorial. But id does not seem to work :(

web.config:

<system.web>
    <authentication mode="Forms">
      <forms name=".DemoAuthCookie" loginUrl="~/Account/Login" timeout="30" 
          slidingExpiration="true" protection="All" />
    </authentication>
</system.web>

View:

<button type="button" onclick="location.href='@Url.Action("Authorize", "Account")';
    return false;" />Login</button>

Controller:

public readonly GoogleClient gClient = new GoogleClient
{
    AuthorizationTracker = new MyAuthorizationTracker(),
    ClientIdentifier = "x...", //client id
    ClientCredentialApplicator = ClientCredentialApplicator.PostParameter("x...") //secret
};

[AllowAnonymous]
public ActionResult Authorize()
{
    IAuthorizationState authorization = gClient.ProcessUserAuthorization();

    // Is this a response from the Identity Provider
    if (authorization == null)
    {
        // no

        // Google will redirect back here
        Uri uri = new Uri("http://localhost:53105/Account/Login");

        // Kick off authorization request with OAuth2 scopes
        gClient.RequestUserAuthorization(returnTo: uri,
            scope: new[] { GoogleClient.OpenId, 
                GoogleClient.ProfileScope, GoogleClient.EmailScope });
    }
    else
    {
        // yes

        var request = WebRequest.Create(GoogleClient.ProfileEndpoint);

        // add an OAuth2 authorization header
        // if you get 403 here, turn ON Google+ API on your app settings page
        request.Headers.Add(
             HttpRequestHeader.Authorization,
             string.Format("Bearer {0}", Uri.EscapeDataString(authorization.AccessToken)));

        // Go to the profile API
        using (var response = request.GetResponse())
        {
            using (var responseStream = response.GetResponseStream())
            {
                var profile = GoogleProfileAPI.Deserialize(responseStream);
                if (profile != null &&
                    !string.IsNullOrEmpty(profile.email))
                    FormsAuthentication.RedirectFromLoginPage(profile.email, false);
            }
        }
    }

    return RedirectToAction("Index", "Home");
}