Begin by ensuring you have Python installed on your system, as it will be used to read the JSON file and send messages to RabbitMQ. You’ll also need the `pika` library, which is RabbitMQ's client library for Python. Install `pika` using pip:
```
pip install pika
```

Load the JSON file that contains the data you wish to transfer. Ensure that the JSON is properly formatted and accessible. You can use Python to read the file:
```python
import json

with open('data.json', 'r') as file:
data = json.load(file)
```

Make sure you have a RabbitMQ server running. You can install RabbitMQ on your local machine or use a remote server. Start the RabbitMQ service using the following command:
```
rabbitmq-server
```
Access the RabbitMQ management console by navigating to `http://localhost:15672/` in your web browser and log in with the default credentials (`guest`/`guest`).

Use the `pika` library to establish a connection to the RabbitMQ server. This involves creating a connection and a channel:
```python
import pika

connection = pika.BlockingConnection(pika.ConnectionParameters('localhost'))
channel = connection.channel()
```

Ensure the queue you intend to use exists. If not, create one. A queue is a buffer that stores messages. Declare it using the channel:
```python
channel.queue_declare(queue='my_queue')
```

Iterate over the JSON data and send each item to the queue using the `basic_publish()` method. Convert the JSON data to a string format:
```python
for item in data:
message = json.dumps(item)
channel.basic_publish(exchange='', routing_key='my_queue', body=message)
print(f"Sent: {message}")
```

After all data has been sent, it’s important to close the connection to RabbitMQ to free up resources:
```python
connection.close()
```

This guide outlines how to manually move data from a JSON file to RabbitMQ using Python, ensuring that you have control over each step without relying on third-party connectors.