Puzzles database can be replaced with another database. Do not forget to set NSUserDefaults for puzzles database. First delete the existing database with this method in AppDelegate: - (void)deleteDatabaseWithName:(NSString*)databaseName
    and then create with this method in AppDelegate: - (void)createDatabaseWithFile:(NSString*)fileName databaseName:(NSString*)databaseName

In addition to puzzles database, there must be one database included.

AppDelegate method createDatabases() has the list of the databases to be parsed in core data.
    Comment databases that you do not want to include.

If you made changes in databases files please delete existing database of that file and import it again.
