ElementHostのWPF要素からホストWinFormのプロパティを変更できるようにするアプローチを誰かが提案できますか?

ElementHostにバインドされたPrismを使用するMVVMアプリケーションがあります。WinFormのタイトルを変更し、WinFormのサイズを変更して、ViewModel内からWinFormを閉じたいと思います。
この記事で説明されているWPF複合コントロールからデータを受信することは理解していますが、ViewModelでどのように機能するかわかりません。
AppはWinFormChartWizardViewModelは、Appのプロパティを変更したいViewModelです。他のすべてはPrismアーキテクチャです。シェル、ブートストラッパーなど。
Public Class App
Public Sub New(ByVal modulesToLoad As List(Of String))
        ' This call is required by the designer.
        InitializeComponent()
        If Application.Current Is Nothing Then
            Dim wpfAppAdapter As New WpfApplicationAdapter
        End If
        '   Load the application modules
        Dim formBootstrapper As New Bootstrapper(modulesToLoad)
        formBootstrapper.Run()
        '   Get the current instance of shell and bind it to the ElementHost
        Dim shellElement = formBootstrapper.Container.Resolve(Of Shell)()
        ehMaster.Child = shellElement
End Sub
End Class
Public NotInheritable Class Bootstrapper
Inherits UnityBootstrapper
Private _modulesToLoad As List(Of String)   '   The modules that we want to load
Public Sub New(ByVal modulesToLoad As List(Of String))
    _modulesToLoad = modulesToLoad
End Sub
Protected Overrides Function CreateShell() As DependencyObject
    Dim shell = Container.Resolve(Of Shell)()
    Return shell
End Function
Protected Overrides Function GetModuleCatalog() As IModuleCatalog
    Dim catalog As ModuleCatalog = New ConfigurationModuleCatalog()
    For Each moduleToLoad As String In _modulesToLoad
        Select Case StringHelper.CleanString(moduleToLoad)
            Case "chartwizardmodule"
                catalog.AddModule(GetType(ChartWizardModule))
        End Select
    Next
    Return catalog
End Function
End Class
Public NotInheritable Class ChartWizardModule
Implements IModule
Private ReadOnly regionManager As IRegionManager
Public Sub Initialize() Implements IModule.Initialize
    regionManager.RegisterViewWithRegion("MainRegion", GetType(MainWindow))
End Sub
Public Sub New(regionManager As IRegionManager)
    Me.regionManager = regionManager
End Sub
End Class
Partial Public Class MainWindow
Private _objChartWizardViewModel As ChartWizardViewModel    '   The chart wizard base view model that controls the rest of the views
Private Sub MainWindow_Loaded(ByVal sender As Object, ByVal e As System.Windows.RoutedEventArgs) Handles Me.Loaded
    Dim objChartWizardViewModel As New ChartWizardViewModel()
    _objChartWizardViewModel = objChartWizardViewModel
    '   Data Context for the Chart Wizard
    Me.DataContext = _objChartWizardViewModel
End Sub
End Class
Public Class ChartWizardViewModel
Implements INotifyPropertyChanged
    '   I need to change the properties of the WinForm (App) from here
End Class