Before beginning the data transfer, ensure both IBM Db2 and Firebolt are set up and accessible. Confirm that you have the necessary permissions to export data from Db2 and import it into Firebolt. Additionally, ensure that your environment has the required command-line tools and drivers installed for both databases.

Use the Db2 export utility to extract the desired data. You can export the data in CSV format, which is commonly supported and easy to manipulate. For example, you can use a command like:
```
db2 EXPORT TO data.csv OF DEL MODIFIED BY NOCHARDEL SELECT FROM your_table
```
This command exports the entire table `your_table` to a CSV file named `data.csv`.

Check the contents of the exported CSV file to ensure that data has been correctly extracted. Open the file in a text editor or use command-line tools like `head` or `cat` to verify the data integrity and correctness.

Before importing data into Firebolt, ensure that you have created the necessary schema and tables to match the structure of the data exported from Db2. Use Firebolt’s SQL command-line or web interface to create tables that match your CSV file structure:
```sql
CREATE DIMENSION TABLE your_table (
column1_name column1_type,
column2_name column2_type,
...
);
```

Firebolt provides a mechanism to import data using the COPY command. First, upload your CSV file to an accessible location, such as an AWS S3 bucket, or you can use local storage if Firebolt is configured to access it directly.

Use the Firebolt COPY command to load data from the CSV file into the Firebolt table. If you uploaded the file to an S3 bucket, the command will look like this:
```sql
COPY INTO your_table
FROM 's3://your-bucket/data.csv'
CREDENTIALS=(aws_key_id='YOUR_AWS_KEY' aws_secret_key='YOUR_AWS_SECRET')
FILE_FORMAT = (TYPE = CSV FIELD_DELIMITER = ',' HEADER = TRUE);
```
Adjust the credentials and file path as necessary for your setup.

After the data has been loaded into Firebolt, perform checks to validate the import. Run basic queries to ensure the data appears correctly, such as counting rows or checking specific column values:
```sql
SELECT COUNT() FROM your_table;
```
This will confirm that the number of rows matches your expectations. You can also perform spot checks on data values to ensure accuracy.

By following these steps, you can successfully transfer data from IBM Db2 to Firebolt without using third-party connectors or integrations. Ensure all operations comply with your organization's data governance and security policies.