Begin by exporting the data from your Coda document. Open your Coda document, navigate to the section with the data you need, and click on the table options. Choose "Download CSV" or "Export" to export your data in a CSV format. This will save the file locally to your computer, which you can then use for importing into Firestore.

Go to the Google Cloud Console (https://console.cloud.google.com) and create a new project or select an existing project where you want to store the data. Make sure that the Firestore API is enabled for your project. If not, navigate to the "API & Services" section, search for "Firestore API," and enable it.

Within the Google Cloud Console, go to the Firestore section and click on "Create database." Choose the start in production mode for security purposes and select the appropriate location setting for your data. This will set up your Firestore database where you will import the Coda data.

Open the CSV file you exported from Coda using a spreadsheet application like Microsoft Excel or Google Sheets. Ensure that the data is cleaned and formatted correctly. Add any necessary columns or headers that match your Firestore database structure. Save any changes you make to the CSV file.

Use a programming language like Python to read the CSV file and insert its contents into Firestore. Install the necessary libraries (`google-cloud-firestore` for Firestore access and `csv` for CSV parsing). Write a script that authenticates with Google Cloud using service account credentials, reads the CSV data, and uploads each row as a document in Firestore. Example:

```python
import csv
from google.cloud import firestore

# Initialize Firestore client
db = firestore.Client()

# Open CSV file
with open('path/to/your/data.csv', mode='r') as file:
reader = csv.DictReader(file)
for row in reader:
# Add data to Firestore
db.collection('YourCollectionName').add(dict(row))
```

Download a service account JSON key from the Google Cloud Console (under IAM & Admin > Service Accounts). Set the environment variable `GOOGLE_APPLICATION_CREDENTIALS` to the path of the JSON key file. Run your script in the terminal or command prompt using Python. The script will parse the CSV and upload each entry to the Firestore collection.

After running the script, verify that all data has been successfully imported into Firestore. Go back to the Firestore section in the Google Cloud Console, and check the collection and documents. Ensure that the data matches what was in the CSV file and that all entries are present and correct.

By following these steps, you can efficiently move data from Coda to Google Firestore without relying on third-party connectors or integrations.