Sub UpdateDocumentsAndTemplates()
Application.ScreenUpdating = False
Dim strFolder As String, strFile As String, strDocNm As String, wdDoc As Document
Dim strTmplt As String, wdTmp As Document, HdFt As HeaderFooter
strDocNm = ActiveDocument.FullName
strFolder = GetFolder
If strFolder = "" Then Exit Sub
strTmplt = "C:\Templates\SomeTemplate.dotm"
Set wdTmp = Documents.Open(strTmplt)
strFile = Dir(strFolder & "\*.doc", vbNormal)
While strFile <> ""
  If strFolder & "\" & strFile <> strDocNm Then
    Set wdDoc = Documents.Open(FileName:=strFolder & "\" & strFile, AddToRecentFiles:=False, Visible:=False)
    With wdDoc
      .AttachedTemplate = strTmplt
      .CopyStylesFromTemplate (strTmplt)
      With .Sections(1)
        For Each HdFt In .Headers
          If HdFt.Exists Then
            If wdTmp.Sections(1).Headers(HdFt.Index).Exists Then
              HdFt.Range.FormattedText = wdTmp.Sections(1).Headers(HdFt.Index).Range.FormattedText
            End If
          End If
        Next
        For Each HdFt In .Footers
          If HdFt.Exists Then
            If wdTmp.Sections(1).Footers(HdFt.Index).Exists Then
              HdFt.Range.FormattedText = wdTmp.Sections(1).Footers(HdFt.Index).Range.FormattedText
            End If
          End If
        Next
      End With
      .Close SaveChanges:=True
    End With
  End If
  strFile = Dir()
Wend
Set wdDoc = Nothing
Application.ScreenUpdating = True
End Sub

Function GetFolder() As String
Dim oFolder As Object
GetFolder = ""
Set oFolder = CreateObject("Shell.Application").BrowseForFolder(0, "Choose a folder", 0)
If (Not oFolder Is Nothing) Then GetFolder = oFolder.Items.Item.Path
Set oFolder = Nothing
End Function