Moving root on ZFS on GELI so GELI is no longer used

[Kralj Karlo]

Trond Endrestøl writes:
> man zfs, searching for zfs snapshot, zfs send, and zfs receive.
>
> My take usually is:
>
> 1. Make sure boot partitions are present and populated on the new disk(s).
>    The same for any swap partitions.

Could you elaborate on this step or refer to relevant man pages?
This is the step I don't know how to do.