Para desproteger un libro de excel, haremos uso de una macro.
Presionamos ALT+F11 para entrar al editor de Aplicaciones de Visual Basic.
Ingresamos a cualquier hoja y agregamos el siguiente código.
Sub DesprotegerLibro() If MsgBox("Realmente desea desproteger el libro actual?", _ vbCritical + vbYesNo + vbDefaultButton2, "DesprotegerLibro") = vbYes Then Dim i As Integer, j As Integer, k As Integer Dim l As Integer, m As Integer, n As Integer On Error Resume Next For i = 65 To 66: For j = 65 To 66: For k = 65 To 66 For l = 65 To 66: For m = 65 To 66: For i1 = 65 To 66 For i2 = 65 To 66: For i3 = 65 To 66: For i4 = 65 To 66 For i5 = 65 To 66: For i6 = 65 To 66: For n = 32 To 126 ActiveWorkbook.Unprotect Chr(i) & Chr(j) & Chr(k) & Chr(l) & Chr(m) & _ Chr(i1) & Chr(i2) & Chr(i3) & Chr(i4) & Chr(i5) & Chr(i6) & Chr(n) If ActiveWorkbook.ProtectStructure = False And ActiveWorkbook.ProtectWindows = False Then MsgBox "El libro está ahora desprotegido", vbInformation + vbOKOnly, "DesprotegerLibro" Exit Sub End If Next: Next: Next: Next: Next: Next Next: Next: Next: Next: Next: Next End If End Sub