Purge Change History Now(Int32, Object) Method
Removes entries from the change log for the workbook.
public void PurgeChangeHistoryNow (int Days, object SharingPassword);
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.
For information on optional parameters, see Optional Parameters in Office Solutions.