To delete data from Salesforce using external application, delete () method is used.
Delete one or more records from your organization’s data. Use delete () to delete one or more existing records, such as individual accounts or contacts, in your organization’s data. The delete () call is analogous to the DELETE statement in SQL.
DeleteResult = connection.delete(ID ids);
where connection is an object of EnterpriseConnection.
Sample JAVA Program to delete data from Salesforce