Begin by manually exporting your data from Xero. Log in to your Xero account, navigate to the relevant reports or data sections (such as invoices, bills, or contacts), and use the export functionality to download the data. Typically, Xero allows exports in CSV or Excel format, which are suitable for this process.

Once you have the exported files, review and clean the data as needed. Ensure that the data is free from errors, duplicates, and irrelevant information. Format the data consistently to facilitate seamless transformation and loading into Databricks.

Access your Databricks account and set up a new workspace or notebook where you will perform data operations. Ensure you have the necessary permissions and resources allocated to handle the data you plan to upload.

Use the Databricks interface to upload your cleaned data files. Navigate to the "Data" section in your workspace, and select "Upload Data." Choose the CSV or Excel files you exported from Xero and upload them to Databricks. This will store your data in the Databricks file system (DBFS).

Use the Databricks SQL interface to create tables that correspond to the structure of your Xero data. Write SQL commands to define table schemas based on the columns of your uploaded files. For example:
```sql
CREATE TABLE xero_invoices (
invoice_id STRING,
date DATE,
amount DECIMAL(10, 2),
status STRING
);
```

Load the data from the uploaded files into the tables you've created. Use SQL or DataFrame operations in Databricks to insert data into your tables. For instance, you could use PySpark:
```python
df = spark.read.csv('/FileStore/tables/xero_invoices.csv', header=True, inferSchema=True)
df.write.format('delta').mode('overwrite').saveAsTable('xero_invoices')
```

After loading data into the Databricks tables, run queries to verify that all data was transferred accurately. Check for any discrepancies or errors. Once verified, consider optimizing your tables using techniques such as partitioning or caching to improve query performance within Databricks.

By following these steps, you can manually move data from Xero to the Databricks Lakehouse without relying on third-party connectors or integrations.