See my response to fundamentally the same inquiry, here:
  https://proconnect.intuit.com/community/lacerte-tax-discussions/discussion/mass-reassignment-of-prep...

Before Lacerte changed the data table structure (TY2018), the plain DBase files were able to be opened & read (and possibly changed, depending on the program you were using) from TY1999 through TY2017.  I used Paradox (originally by Borland, currently part of the Corel WordPerfect Office Suite package), and it looks like I started scripting mass-changes to Preparer/Staff Preparer not later than mid-January of 2010.

Currently I would do this by setting up an ODBC connection, and then making mass changes as before.  For details, read the link above.



Robert Kirk
LTUGtools