Change Multiple date formats to one format

Sub ConvertDateFormat()
Dim DtRange As Range
Dim oCell As Range
Dim oTxt As String
  If Selection.Cells.Count = 1 Then
    Set DtRange = ActiveCell
  Else
    Set DtRange = Selection
  End If
With Application
  On Error Resume Next ' In case there are no xlConstants or convertible dates in DtRange
  For Each oCell In DtRange.SpecialCells(xlConstants)
    oTxt = "'" & oCell.Text
    oCell.Value = Mid(oTxt, 2, .WorksheetFunction.Find("/", oTxt) - 2) & "/" & _
    Mid(oTxt, .WorksheetFunction.Find("/", oTxt) + 1, .WorksheetFunction.Find("/", _
    .WorksheetFunction.Replace(oTxt, .WorksheetFunction.Find("/", oTxt), 1, " ")) - _
    .WorksheetFunction.Find("/", oTxt) - 1) & "/" & Right(oTxt, Len(oTxt) - _
    .WorksheetFunction.Find("/", .WorksheetFunction.Replace(oTxt, _
    .WorksheetFunction.Find("/", oTxt), 1, " ")))
  Next oCell
End With
End Sub