To import a PokerTracker v2 PostgreSQL database to your active PokerTracker 3 database, click Databasein the main menu then go Convert and Convert PokerTracker 2 Database. A new window will appear that lists all of the PT2 databases on your computer. Select the PT2 database that you want converted to your active PT3 database and click OK. You will be prompted with a notice asking if you would like to continue. Click Yes. You can view the status of the conversion process via the Import tabs window.
Note: Currently, you can only convert a PostgreSQL database and hands where the hand histories have been saved in the database. To convert an Access database, you should convert your PT2 Access database to PostgreSQL within PT2 then convert this database within PokerTracker 3 or export the hand histories from PT2 using Utilities -> Export Hand Histories to File.