How to change the sub-item text of the selected item in the list view in WPF?

[VahidEra]

Hi guys,
I have a List View in my project that I solved many problems with the help of my dear friend @miloush.
Like this:#7430
There are four columns in my list view(No. , Start Time, End Time,Text) and I want to change the text of the selected item in the fourth column, that is, the text column, which I have named as TextSub in the MyRowData class

Public Class MyRowData
        Public Property No As String
        Public Property StartTime As String
        Public Property EndTime As String
        Public Property Duration As String
        Public Property TextSub As String

End Class

and According to the training of my dear friend @miloush, I have used this code to add items to list view:

listViewSecondSub.Items.Add(New MyRowData With {.No = "1" , .StartTime = "00:03:43,360", .EndTime = "00:03:44,360" _
                                       , .TextSub = "This is a test"})

And to get text of the selected item in the fourth column, I use this cod:

CType(listViewSecondSub.SelectedItems(0), MyRowData).TextSub

And now I want to change the textsub in selected item at runtime, for example to replace "this is a test" with something else.
How should I do this?