Begin by logging into your Recruitee account. Navigate to the section where your data is stored, such as candidates, job postings, or any other relevant sections. Use the export functionality to download the data in a CSV or JSON format. This feature is usually found in the 'Reports' or 'Data Export' section. Save the exported file on your local machine.

If you haven't already set up Firestore, you need to do so. Log into the Google Cloud Platform (GCP) Console. Create a new project or select an existing one. Navigate to the Firestore section and choose the appropriate mode for your database (Native mode is recommended for new projects). Set up your Firestore database by creating any necessary collections and documents that will correspond to the data structure you exported from Recruitee.

Open your exported file and inspect the data structure. Ensure that the fields and data types align with how you want them stored in Firestore. If needed, clean and format the data using a spreadsheet application (for CSV) or a text editor (for JSON) to match the Firestore schema. This step is crucial to avoid errors during the import process.

To interact with Firestore directly, install the Google Cloud SDK on your local machine. This will allow you to use the command line tools to perform operations on your Firestore database. Follow the installation instructions provided on the [Google Cloud SDK webpage](https://cloud.google.com/sdk/docs/install).

After installation, open a terminal or command prompt. Authenticate your Google Cloud SDK with your Google account using the command:
```
gcloud auth login
```
Follow the on-screen instructions to complete the authentication process. Ensure that your Google account has the necessary permissions to access and write data to Firestore.

Use a programming language like Python or Node.js to write a script that reads data from your CSV or JSON file and imports it into Firestore. For Python, you can use the `google-cloud-firestore` package. Begin by setting up the Firestore client and then iterate over your data file, using the `add` or `set` methods to insert documents into the corresponding Firestore collections.

Example using Python:
```python
from google.cloud import firestore
import csv

# Initialize Firestore client
db = firestore.Client()

# Open your CSV file
with open('your-data-file.csv', mode='r') as file:
reader = csv.DictReader(file)
for row in reader:
# Reference your collection and add documents
db.collection('your-collection-name').add(row)
```

Once the script completes, go back to the Firestore console in GCP and verify that all the data has been imported correctly. Check for any errors or missing fields. If errors occurred during the import, debug them by reviewing the log outputs from your script, adjusting the data formatting, or modifying the script logic as needed. Repeat the import process if necessary until all data is correctly stored in Firestore.

By following these steps, you can manually transfer data from Recruitee to Google Firestore without relying on third-party connectors or integrations.