Locate the IP for the BMC/IPMI interface of the system and open a browser to its IP
Log in: userid/password: admin/password
Select 'Update' from the left menu
Select the dropdown (Could Be ROM or BIOS depending on WebUI version)
Locate the BIOS file (usually has RBU extension). Choose Upload
Wait for it to reach 100% complete. Then Remove power cord, wait 5 minutes, reconnect power and boot.