Here's one way to protect or unprotect a sheet by entering the passwords in a cell. Try this in your worksheet module. Before doing so, be sure to unlock cell A1 or whatever cell(s) you want to have access to. Modify the passwords as you wish, although the ones in this example are excellent choices.
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Private Sub Worksheet_Change(ByVal Target As Range)
If [A1] = "Tom" Then
ActiveSheet.Unprotect
ElseIf [A1] = "Urtis" Then
ActiveSheet.Protect
End If
End Sub
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