Begin by logging into your Aha! account and navigate to the data or reports section. Use the export functionality to download the data you need, typically in a CSV or Excel format. Save the exported file to a location on your computer where you can easily access it.

If you haven't already, install DuckDB on your system. You can download the appropriate version from the [official DuckDB website](https://duckdb.org/). Follow the installation instructions for your operating system to get it set up.

Open the exported CSV or Excel file from Aha! and ensure it is clean and properly formatted. Check for any inconsistencies, such as missing headers or incorrect data types, and correct them. Save the file in a CSV format if it isn't already, as this format is widely compatible with DuckDB.

Open a terminal or command prompt and start DuckDB. You can do this by simply typing `duckdb` if it's in your system's PATH, or by navigating to the DuckDB executable and running it.

In DuckDB, create a new database file where you will store the imported data. You can do this by entering the command:
```
CREATE DATABASE 'my_database.duckdb';
```
Replace `'my_database.duckdb'` with your desired database name and path if necessary.

Use DuckDB's SQL interface to import the CSV file into a new table. First, specify the database you created:
```
ATTACH 'my_database.duckdb' AS mydb;
```
Then, run the import command:
```
CREATE TABLE mydb.my_table AS SELECT * FROM read_csv_auto('path/to/your/file.csv');
```
Replace `'path/to/your/file.csv'` with the actual path to your CSV file and `'my_table'` with your desired table name.

After the import, verify that the data has been correctly transferred by running a simple query:
```
SELECT * FROM mydb.my_table LIMIT 10;
```
This will display the first 10 rows of your table, allowing you to check for accuracy and completeness of the data import.

By following these steps, you can successfully transfer your data from Aha! to DuckDB without the need for third-party connectors or integrations.