No, there really isn't a way to do this, easy or hard. You could export the hands from the Access databases to text files and then get rid of the current hhdb.mdb file and download a new one and then reimport these files into new Access databases. But that would be a big PITA.
That's also a PITA too because basically you would have to use MS Access to link in the other ptrackX.mdb files and then compare the record in the hand_histories table (based on game_number, site_id and import_date) and compare that to the data in the game table of the ptrack files to see if there exists a record with the same values and if not, then you can delete that record from the hhdb file.