Remove the disks, insert new disks, boot to CTRL-R, and clear the configuration or delete the existing VD's. Once cleared, you can then create a new RAID 1 VD, then install your new operating system.
i have a PE T320 raid 5. i want to remove the current 3 drives, i don't  need to save anything ...as well as the raid 5. and install 2 new drives with a raid 1. please assist me with this . Thank You !!! Steve E
T320 Raid 5