Thank you for using the Support Forum. Please take a look at this document that explains how the memory in your machines work. Then follow the instructions for Image Overwrite for WorkCentre 58xx and WorkCentre 57xx. If you need further information please consider contacting your support centre for further assistance.
Easily done on the 58XX
as admin go to Machine Status > Tools > Device Settings > General > Erase Customer data and run that, all settings will be lost.
That is not a feature on older products like the 57XX, for that you would need to do an Altboot, no data backup , or get Xerox to do one. It is a manual process done via booting from a USB key with a very specific file structure. The altboot process is identical for both devices, the only thing that would change is the firmware file for each family.
Send me a PM if needed.