recreate RAID -- what about device?

We've got an RA3000 with 2 HSZ22 controllers configured as RAID0+1.  We
want to recreate this as RAID5.  I've unmounted the file systems,
removed the filesets, and removed the AdvFS file domain.  Do I need to
do anything else at the OS level before I reconfigure the raidset?
i.e., dsk5 is the device that sees the HSZ22 controllers:
 
 HWID: Device Name          Mfg      Model            Location
 
------------------------------------------------------------------------
------
   47: /dev/disk/dsk5c      DEC      HSZ22    (C) DEC bus-1-targ-1-lun-0

 
Do I need to do anything to dsk5 before changing the raid config?


Thanks!
Andy