Workbook.PurgeChangeHistoryNow Method (Int32, Object)
Removes entries from the change log for the workbook.
Assembly: Microsoft.Office.Tools.Excel (in Microsoft.Office.Tools.Excel.dll)
The number of days that changes in the change log are to be retained.
The password that unprotects the workbook for sharing. If the workbook is protected for sharing with a password and this argument is omitted, the user is prompted for the password.