Raid 0 to Raid 1 Thunderbolt

I have a WD Thunderbolt two disk enclosure. Currently it’s set up as a two disk Raid 0 stripe using Disk Utility.

For additional data protection, I’d like to buy another two drives and mirror the existing Raid 0 stripe without losing or Migrating any data from the existing Raid 0 stripe. i.e upgrade to RAID 10.

I’m running El Capitan, 10.11.3

Is this possible to change from a two disk stripe to a 4 disk mirror without losing/migrating data off the RAID’ed volume?

Does anyone have a procedure to do this?

Thank you!

At the time of this post WD Drive Utilities does not support creating a single RAID shared volume between two different units.

Thanks Trancer, but I’m not trying to use the WD Drive utilities to do that. I’m trying to do it with The OS X Disk manager…
I was hoping someone on this forum knew how to do this. It looks like it’s possible via the Man page for disk manager’s command line.