Assuming the number only appears once in the link path, then Paul's code can be modified e.g.
Code:
Sub Demo()
Application.ScreenUpdating = False
Dim i As Long
With ActiveDocument
For i = .Shapes.Count To 1 Step -1
With .Shapes(i)
If Not .LinkFormat Is Nothing Then
With .LinkFormat
.SourceFullName = Replace(.SourceFullName, "046", "048")
End With
End If
End With
Next
For i = .InlineShapes.Count To 1 Step -1
With .InlineShapes(i)
If Not .LinkFormat Is Nothing Then
With .LinkFormat
.SourceFullName = Replace(.SourceFullName, "046", "048")
End With
End If
End With
Next
End With
Application.ScreenUpdating = True
End Sub