Begin by exporting data from MongoDB into a format that can be easily transferred and imported into other systems. Use the `mongoexport` utility, which is provided with MongoDB, to export collections into JSON or CSV files. For example, to export a collection to a JSON file, run:
```bash
mongoexport --db yourDatabase --collection yourCollection --out collection.json
```
Adjust the parameters to match your database and collection names.

Review the exported data to ensure it is in the correct format for Firebolt. If the data was exported in JSON format, consider converting it to CSV if necessary, as CSV is often easier to manage for bulk imports. Use a script or tool like `jq` for JSON processing if transformation is needed.

Before importing data, ensure that your Firebolt environment is set up and ready for data ingestion. This involves creating a database and setting up the necessary tables that match the schema of your exported data. Use SQL commands within the Firebolt console to create tables:
```sql
CREATE TABLE your_table (
column1 datatype,
column2 datatype,
...
);
```

Move your prepared data files to a storage location accessible by Firebolt. Typically, this involves uploading the files to an Amazon S3 bucket or similar cloud storage service. Use AWS CLI or a similar tool to upload files:
```bash
aws s3 cp collection.json s3://your-bucket-name/
```

In Firebolt, create an external table that points to the data files stored in your cloud storage. This table acts as a reference to read the data from your storage location. Use a command like:
```sql
CREATE EXTERNAL TABLE ext_table (
column1 datatype,
column2 datatype,
...
)
URL = 's3://your-bucket-name/collection.json'
OBJECT_PATTERN = '*.json'
TYPE = (JSON);
```

With the external table set up, you can now import data into Firebolt. Use the `INSERT INTO` command to move data from the external table into your main Firebolt table:
```sql
INSERT INTO your_table
SELECT * FROM ext_table;
```
This process reads the data from your storage and loads it into the Firebolt database.

After the import is complete, verify the integrity of the data by running queries to check counts, sums, or other aggregations to ensure everything was transferred correctly. Once verified, you can clean up any temporary files or external table definitions if they are no longer needed. Perform necessary maintenance like removing the external table:
```sql
DROP EXTERNAL TABLE IF EXISTS ext_table;
```

By following these steps, you will successfully move data from MongoDB to Firebolt without relying on third-party connectors or integrations.