Locate the URL of the RSS feed from which you want to fetch data. RSS feeds are typically XML files that can be accessed via a URL. Ensure you have the correct URL to avoid errors in data retrieval.

Use a programming language, such as Python, to request and retrieve the RSS feed data. You can use the `requests` library in Python to perform an HTTP GET request to the RSS feed URL and obtain the raw XML data.

Parse the retrieved XML data to extract meaningful information. Use a library like `xml.etree.ElementTree` in Python, which can parse XML and help you navigate through the elements to retrieve desired data fields such as title, link, description, and publication date.

Once you've extracted the necessary information, structure the data in a dictionary format that can be easily converted to JSON. Organize each RSS item into a dictionary with keys corresponding to the data fields you extracted.

Convert the structured dictionary data into JSON format. In Python, you can use the `json` library's `dumps` method to serialize the dictionary into a JSON string, ensuring that the data is in a format that can be written to a JSON file.

Save the JSON string to a local file on your machine. Open a new file in write mode using Python's built-in `open` function, and write the JSON data to this file. Ensure the file is named with a `.json` extension and is saved in the desired directory.

To ensure the data is regularly updated, automate the script using a task scheduler. On Windows, you can use Task Scheduler, while on macOS and Linux, you can use cron jobs. Schedule the script to run at intervals that suit your data update needs, such as hourly or daily.

By following these steps, you can effectively move data from an RSS feed to a local JSON file without relying on third-party connectors or integrations.