Delete Every Nth Row

Hello everybody
I found this code

Public Sub DeleteEveryNthRow(Optional N As Long = 2)
        'The default is to delete every 2nd row
        Dim rDelete As Range
        Dim i As Long
        With ActiveSheet
            Set rDelete = .Rows(N)
            For i = 2 * N To .UsedRange.Rows.Count Step N
                Set delRange = Union(rDelete, .Rows(i))
            Next i
        End With
        rDelete.Delete
    End Sub

It's supposed to delete every Nth row ..
I don't know how to use it?
I tried a lot but failed