First, ensure you have a CockroachDB client installed and configured on your machine. You can use the `cockroach` command-line tool to interact with your database. Verify the connection by running a simple query like `cockroach sql --insecure --execute="SHOW DATABASES;"` to ensure you can connect to your CockroachDB instance.

Use the CockroachDB SQL client to extract the data you intend to move. Execute a query to fetch the desired records, and output this data to a file. For example, you can run `cockroach sql --insecure --execute="SELECT * FROM my_table;" > data.csv` to extract data into a CSV format. Ensure your SQL query fetches all the necessary data.

Ensure that your Kafka environment is up and running. You need access to a Kafka broker and ZooKeeper. Start Kafka by running `bin/zookeeper-server-start.sh config/zookeeper.properties` and `bin/kafka-server-start.sh config/server.properties` from your Kafka installation directory.

Create a Kafka topic where the data will be published. Use the Kafka command-line tool to create a topic by executing `bin/kafka-topics.sh --create --topic my_topic --bootstrap-server localhost:9092 --partitions 1 --replication-factor 1`. Replace `my_topic` with your desired topic name.

Write a script in a language like Python or Bash to read the extracted data and publish it to the Kafka topic. Using Python's Kafka library, you can read the `data.csv` file and send each row to Kafka. Here is a simple example using Python:
```python
from kafka import KafkaProducer
import csv
producer = KafkaProducer(bootstrap_servers='localhost:9092')
topic = 'my_topic'
with open('data.csv', mode='r') as file:
csv_reader = csv.reader(file)
for row in csv_reader:
message = ','.join(row)
producer.send(topic, value=message.encode('utf-8'))
producer.flush()
producer.close()
```

Execute the script you created in the previous step to begin transferring data from the CSV file to the Kafka topic. Ensure the script runs without errors and all intended data is published to Kafka.

Finally, verify that the data has been successfully transferred to Kafka. Use the Kafka consumer console to read messages from the topic by executing `bin/kafka-console-consumer.sh --topic my_topic --from-beginning --bootstrap-server localhost:9092`. This will display messages from the beginning of the topic, allowing you to confirm the data is correctly published.
By following these steps, you can transfer data from CockroachDB to Kafka without relying on third-party connectors or integrations.