Links

For Each objField In ActiveDocument.Fields 
   objField.LinkFormat.BreakLink 
Next objField 

Public Sub TestThis() 
    Call changeSource("", "") 
End Sub 

Public Sub changeSource(ByVal sOldFileName As String, _ 
                        ByVal sNewFileName As String) 
Dim icount As Integer 
Dim iloop As Integer 
Dim sfilename As String 

    On Error GoTo ErrorHandler 
    icount = ActiveDocument.Fields.Count 
    
    For iloop = 1 To icount 
        If (ActiveDocument.Fields(iloop).Type = wdFieldLink) Then 
            Debug.Print ActiveDocument.Fields(iloop).OLEFormat.ClassType 
            Debug.Print ActiveDocument.Fields(iloop).OLEFormat.Label 
            Debug.Print ActiveDocument.Fields(iloop).OLEFormat.DisplayAsIcon 
        
            sfilename = ActiveDocument.Fields(iloop).LinkFormat.SourceFullName 
            
            ActiveDocument.Fields(iloop).LinkFormat.SourceFullName = _ 
                Replace(sfilename, sOldFileName, sNewFileName) 
        End If 
    Next iloop 

    Exit Sub 
ErrorHandler: 
    Call MsgBox(Err.Number & " - " & Err.Description) 
End Sub