This repair guide explains how to replace the wheel module on a 500 series Roomba. For details on how to first disassemble your Roomba, please see Roomba 500 Series Servicing and Repair Guide Chapter 3: How to Open Up Roomba. Some of the 500 series Roombas are pictured below:
This is a companion discussion topic for the original entry at https://community.robotshop.com/index.php/blog/show/chapter-11-how-to-replace-roomba-500-series-motherboard