There is an option to transfer letters under settings, transfer prior year settings.  I'm not sure if the option to copy the "client letters" includes the database reports.  I would try that first but I don't want to test it by messing up my letters at this point.

I have copied the database reports forward manually.  Go to your ?:\lacerte\19tax\options19\ folder and copy your TMLT*.* to ?:\lacerte\20tax\options20\ folder.

Rename the extension  TMLTR*.*w0  on each TMLTR file