To interact with Trello and extract data, you need to set up API access. Start by logging into your Trello account and navigating to the Trello Developer Portal. Create a new API key and token which will allow you to authenticate API requests. Save these credentials securely as they will be used to fetch data from Trello.

With the API key and token, you can now make HTTP requests to Trello's API. Use a tool like `curl` or a scripting language like Python with the `requests` library. For example, to fetch all cards from a specific board, make a GET request to `https://api.trello.com/1/boards/{boardId}/cards?key={yourApiKey}&token={yourApiToken}`. Parse the JSON response to extract relevant data fields.

Once you have the Trello data, you may need to transform it to fit Redis's data structure. Redis is a key-value store, so decide how you want to store Trello data, such as using card IDs as keys and card details as values. You might need to process the JSON data using scripts to map it into the desired format.

Ensure Redis is installed and running on your machine or server. You can download and install Redis from its official website. Once installed, start the Redis server using the `redis-server` command. Confirm that Redis is running by connecting to it using `redis-cli`.

Choose a scripting language like Python to interact with Redis. Install the Redis client library for your chosen language, such as `redis-py` for Python, using `pip install redis`. Establish a connection to the Redis server in your script to prepare for data insertion.

Iterate over the transformed Trello data and insert it into Redis using your script. Use Redis commands like `SET` for simple key-value pairs or `HMSET` for storing hashes if you want to store multiple fields per card. For example, `redis_client.set(card_id, card_data)` or `redis_client.hmset(card_id, card_fields_dict)`.

After inserting data, verify that it has been stored correctly in Redis. Use the `redis-cli` to connect to your Redis instance and run commands like `GET` or `HGETALL` to retrieve and check the data. Ensure that all Trello data is accurately reflected in Redis, and make any necessary adjustments if there are discrepancies.

By following these steps, you can manually transfer data from Trello to Redis without relying on external connectors or integrations.