Begin by setting up access to the Xero API. Go to the Xero Developer portal and create a new app. This will provide you with OAuth 2.0 credentials, including a Client ID and Client Secret, which you will need to authenticate your requests to the Xero API.

Use the OAuth 2.0 credentials to authenticate with Xero. You can achieve this using a scripting language like Python. Libraries such as `requests` can be used to handle HTTP requests. Obtain an access token and make API requests to retrieve the data you need, such as invoices, contacts, or transactions.

Once you have the data from Xero, transform it to match the schema required by DynamoDB. DynamoDB is a NoSQL database, so your data will need to be in JSON format. Ensure each data item has a unique primary key, which is required by DynamoDB.

Log into your AWS Management Console and navigate to DynamoDB. Create a new table specifying the primary key that matches the transformed data from Xero. This will involve defining partition keys and optionally sort keys, depending on your data structure.

Install the AWS SDK for your chosen programming language (e.g., Boto3 for Python). This SDK will allow you to interact with DynamoDB programmatically. Configure the SDK with your AWS credentials to ensure you have the necessary permissions to write data to your DynamoDB table.

Using the AWS SDK, write a script to insert the transformed JSON data into your DynamoDB table. Use batch writing to handle larger datasets more efficiently and ensure that your script handles any potential errors or exceptions during the writing process.

After the data is loaded into DynamoDB, verify that the data transfer was successful. Run queries on the DynamoDB table to check that all expected records are present and the data matches what was extracted from Xero. This step ensures data integrity and consistency in your migration process.