This document provides a step-by-step guide for using LSMW to update customer master records in SAP. It demonstrates the process using both a transaction recording and a standard SAP object. The recording method involves recording a transaction to update customer data and then mapping source fields to target fields. The standard object method uses a predefined batch input interface to map source fields to multiple target structures. In both cases, LSMW reads source data, converts it to the internal format, creates a batch input session, and runs the session to update customer records in SAP.