Not quite sure why you are trying to "force firmware update". Start with the boot drive and put in a 2nd blank one and format it. Shutdown, take the 2nd drive out and replace it with the 3rd. Shutdown take the 3rd drive out and replace it with the 4th. Each of these drives should now be bootable independently. Now put all four in. You should have 4 individual drives without RAID. Then "Restructure Raid Array" into Raid 5 with 4 drives.
