Determine the API endpoint provided by the news data source. You will need access credentials (like an API key) and the documentation to understand the available endpoints, request methods, and response formats.

Ensure you have a programming environment set up that can handle HTTP requests and JSON data. Common languages for this task include Python, JavaScript (Node.js), or any other language you're comfortable with that supports HTTP requests and JSON parsing.

Use your chosen programming language to write a script that makes a GET request to the news data API endpoint. Include any necessary authentication details in the request header, such as an API key.

```python
import requests

url = "https://api.newsdata.io/v1/news" # Example URL
headers = {"Authorization": "Bearer YOUR_API_KEY"}

response = requests.get(url, headers=headers)

if response.status_code == 200:
news_data = response.json()
else:
print("Failed to retrieve data:", response.status_code)
```

Once you have the data in JSON format from the API response, parse it to extract the information you need. This step involves navigating the JSON structure to access specific fields or attributes.

```python
articles = news_data.get('articles', [])
for article in articles:
print(article['title'], article['description'])
```

If necessary, transform the data into a new structure that suits your needs. Perhaps you want to select only certain fields or rearrange them for better organization before saving to a JSON file.

```python
transformed_data = [{"title": article['title'], "description": article['description']} for article in articles]
```

Use file handling capabilities in your programming language to write the transformed data to a local JSON file. Ensure proper file permissions and handling to prevent data corruption.

```python
import json

with open('news_data.json', 'w', encoding='utf-8') as json_file:
json.dump(transformed_data, json_file, ensure_ascii=False, indent=4)
```

Implement a scheduling mechanism (e.g., cron jobs for Unix-based systems or Task Scheduler for Windows) to run your script at regular intervals if you need continuous data updates. This ensures your local JSON file stays current with the latest news data.

- For a cron job: `0 * * * * /usr/bin/python3 /path/to/your/script.py`
- For Task Scheduler: Use the "Create Basic Task" wizard and point it to your script.

By following these steps, you should be able to successfully move data from a news data API source to a local JSON file without relying on third-party connectors or integrations.