ASP NET Users Without Repository

// Service that will use users
 public class QuizesService : IQuizesService
{
    private readonly IDbRepository<Quiz> quizzes;
    private readonly UserManager<ApplicationUser> manager;
    private readonly IIdentifierProvider identifierProvider;

    public QuizesService(
        IDbRepository<Quiz> quizzes,
        IIdentifierProvider identifierProviders,
        UserManager<ApplicationUser> manager)
    {
        this.quizzes = quizzes;
        this.identifierProvider = identifierProviders;
        this.manager = manager;

        // Now you can access users
        var user = this.manager.Users.FirstOrDefault(u => u.Email == "nesthosi");
        this.manager.Delete(user);
    }
}

// In Autofac
private static void RegisterServices(ContainerBuilder builder)
{
    builder.Register(x => new ApplicationDbContext())
        .As<DbContext>()
        .InstancePerRequest();
    builder.Register(x => new HttpCacheService())
        .As<ICacheService>()
        .InstancePerRequest();
    builder.Register(x => new IdentifierProvider())
        .As<IIdentifierProvider>()
        .InstancePerRequest();

    // Add This
    builder.RegisterType<UserStore<ApplicationUser>>()
        .As<IUserStore<ApplicationUser>>();
    builder.RegisterType<UserManager<ApplicationUser>>();
    // Up to here

    var servicesAssembly = Assembly.GetAssembly(typeof(IQuizesService));
    builder.RegisterAssemblyTypes(servicesAssembly)
        .AsImplementedInterfaces();

    builder.RegisterGeneric(typeof(DbRepository<>))
        .As(typeof(IDbRepository<>))
        .InstancePerRequest();

    builder.RegisterAssemblyTypes(Assembly.GetExecutingAssembly())
        .AssignableTo<BaseController>().PropertiesAutowired();
}