Migrate to different FS layout of OpenBSD

Folks,

I'm looking for a way to migrate to different layout some OpenBSD systems.

All of them has RAID0 and as far as I think I may something like this:

1. Remove second disk from RAID.
2. Build a new RAID0 on the second disk.
3. Make desires layout on the second RAID.
4. dump | restore
5. Boot from the second RAID.
6. Add the first disk to the second RAID.

I have re-read https://www.openbsd.org/faq/faq14.html a few times and I
feel that this is quite risky.

So, questions:
1. Has anyone done something like this before?
2. Do you have any instruction or that to expect?

Thanks in advance.

--
wbr, Kirill