The main module motherboard is a cold-service component that can be replaced only by authorized service personnel.
The server software keeps track of the location of some components, such as the hard drives and RAID expansion modules, so you might have to reinstall the software on some components if they are moved to different locations in the main module. Make a note of the location of the components in the main module and install these components in the same locations in the new main module so that you do not have to reinstall software on any of these components.
See Prevent ESD Damage.
See Remove the System Configuration PROM. Put the system configuration PROM aside to install it on the replacement motherboard.