Unprotect Method [Excel 2003 VBA Language Reference]
Removes protection from a sheet or workbook. This method has no effect if the sheet or workbook isn't protected.
expression Required. An expression that returns a Chart, Workbook, or Worksheet object.
Password Optional Variant. A string that denotes the case-sensitive password to use to unprotect the sheet or workbook. If the sheet or workbook isn't protected with a password, this argument is ignored. If you omit this argument for a sheet that's protected with a password, you'll be prompted for the password. If you omit this argument for a workbook that's protected with a password, the method fails.
If you forget the password, you cannot unprotect the sheet or workbook. It's a good idea to keep a list of your passwords and their corresponding document names in a safe place.
This example removes protection from the active workbook.