Deleting your RAID through the PERC BIOS is a pretty quick process. This tutorial will show you how to delete a Virtual Disk and HERE is how to create a Virtual Disk.
This tutorial applies to: Dell PERC 5/E, 5/i, 6/E, 6/i, H300 series, H700 series, and H800 series
Boot into the RAID Controller BIOS by pressing “Ctrl-R” during POST
Once it is loaded, select your controller under VD Mgmt and press F2 to bring up the option window. Highlight Delete VD and press Enter.
Press OK to confirm the deletion of the Virtual Disk