To begin, ensure you have a running instance of ElasticSearch. This can be hosted locally or on a server. Verify that you have the necessary access credentials (host URL, port, username, password) to interact with ElasticSearch's REST API.

Before sending data, create an index in ElasticSearch where the data will be stored. Use Kibana or the ElasticSearch API to create an index. The API request could look like this:
```bash
PUT /your_index_name
{
"settings": {
"number_of_shards": 1
},
"mappings": {
"properties": {
"your_field": { "type": "type" }
}
}
}
```

If not already installed, set up n8n on your system. Start the n8n workflow automation tool by running `n8n start` in your terminal. Access the n8n editor via `http://localhost:5678` to begin building your workflow.

In n8n, add an HTTP Request node to your workflow. This node will be used to communicate with the ElasticSearch API. Configure the HTTP method to `POST` and set the URL to your ElasticSearch index endpoint (e.g., `http://your_elasticsearch_host:9200/your_index_name/_doc`). Set the authentication method to Basic Auth if required, providing your username and password.

Use other nodes in n8n to prepare and structure the data you want to send to ElasticSearch. You might need to use the Set node to format the data fields appropriately. Ensure the JSON structure aligns with the ElasticSearch index mappings defined earlier.

Connect the prepared data node to the HTTP Request node. In the HTTP Request node, map the prepared data fields to the JSON body. This setup will send the data to the specified ElasticSearch index when the workflow is executed.

Execute the n8n workflow to initiate the data transfer. After execution, verify the data in ElasticSearch using Kibana or by querying the ElasticSearch API. You can run a GET request like:
```bash
GET /your_index_name/_search
```
This will confirm whether the data has been successfully indexed.
By following these steps, you should be able to move data from n8n to ElasticSearch without using third-party connectors or integrations.