Begin by exporting the necessary data from WooCommerce. WooCommerce provides built-in tools to export data such as orders, products, and customers. Navigate to the WooCommerce dashboard, select "Export," and choose the data you need. Save the exported data in CSV format, ensuring that the structure is consistent and includes all necessary fields for your analysis in ClickHouse.

Once the data is exported, review the CSV files to ensure consistency and completeness. Clean the data by removing any unnecessary columns, correcting any errors, and standardizing formats (e.g., date formats, currency formats). This step is crucial for maintaining data integrity when importing into ClickHouse.

Ensure that your ClickHouse server is installed and running. If not already installed, you can download and set it up on your server. Installation guides are available on ClickHouse's official documentation. Once installed, verify the server is running by executing a simple query through the ClickHouse client or a SQL interface.

Use the ClickHouse client to create a new database to store your WooCommerce data. For example:
```sql
CREATE DATABASE woocommerce_data;
```
Next, create tables that match the structure of your WooCommerce data. Define the schema carefully, specifying data types that correspond to the data in your CSV files. For example:
```sql
CREATE TABLE woocommerce_data.orders (
order_id UInt32,
customer_id UInt32,
order_date Date,
total_amount Float32
) ENGINE = MergeTree()
ORDER BY order_id;
```

Transfer the prepared CSV files to the server where ClickHouse is installed. This can be done using secure copy (scp) or any other file transfer method that suits your infrastructure. Ensure the files are placed in a directory accessible by ClickHouse.

Use ClickHouse's command-line tool to import the CSV data into the corresponding tables. You can use the `clickhouse-client` with the `--query` option to load data:
```bash
clickhouse-client --query="INSERT INTO woocommerce_data.orders FORMAT CSV" < /path/to/your/orders.csv
```
Repeat this process for each CSV file, ensuring that the imported data is correctly matched to the respective table.

After importing, verify that the data has been correctly transferred by running several validation queries. Check row counts, data types, and sample entries to ensure accuracy. For example:
```sql
SELECT COUNT(*) FROM woocommerce_data.orders;
```
Compare the result with your original data to confirm completeness. Additionally, run queries to spot-check specific entries for correctness.

By following these steps, you can effectively transfer data from WooCommerce to a ClickHouse data warehouse without relying on third-party connectors or integrations.