To import a Holdem Manager database go to Tools -> Setup Assistant from the main menu.
From here, scroll down and select Convert Holdem Manager Database.
Select the database(s) you wish to import from the Available Databases section. You must also make sure that your PostgreSQL settings are correct. To change them, click the blue Change link. Lastly, select which PokerTracker 4 database you would like your Holdem Manager database(s) imported into. Once you've made all of your selections, click OK.
For bigger databases this process can take a considerable amount of time. Please allow PokerTracker to finish for optimal results.
If you have any issues at all while converting your Holdem Manager database(s) please contact PokerTracker support so that we can help you get your full database converted correctly.