How do I backup and restore Plex Media Server on WD PR2100 ?



I'm looking at changing the disks in my PR2100 NAS - or more specifiaclly changing the RAID setup from mirrored to striped, as I now need the extra capacity!! (I already backup my media onto other external drives, so I'm less concerned about one disk failing.)

However, to do this, I assume I will lose everythiing on the drive(s) when I change the RAID setup? With this in mind, how do I backup my Plex media server and restore it again once I've changed the disk setup?