The RD Customer Package software allows PRSS and MPKBY agents to maintain a database of customer accounts, prepare bulk payment lists, and provide the lists as text files to the post office for uploading. The document outlines the installation process, how to initialize the software with agent details, configure interest rates and office settings, add customer accounts, prepare bulk lists, and copy the lists to a removable drive to submit to the post office. Agents can also perform additional tasks like adding or deleting accounts and entering transactions in the software.