erm shot my foot off with zfs, q on rescue

[Russell L. Carter]

Hi,

So I misfired and hosed my 10/stable zfs / mounts by running

zfs set mountpoint=/ zroot/zetc

so that now I don't seem to actually have any of the uh mandatory
system directories visible.  (turns red)

No emergency thankfully, I've got three border gateways and just got
all three happily configured so if I had to I could just reinstall
this poor innocent one that I accidentally shot in the face.

But as it happens I pulled it and have it interfaced with a keyboard
and monitor and have booted a USB 10.3 stable install image.  I
dropped into the shell, and ran zfs list and it comes up with nothing.

My thought is I'll just do zfs destroy zroot/zetc once I get the zroot
pool imported.  So the questions are, how to import the existing
zpools from the install image shell and once that is done, what is the
best strategy for undoing the damage?

(I absolutely *love* zfs, just got done moving a fully configured
  poudriere installation to another box via zrep, wow is all I can
  say.  My botch here comes from wanting to make a lot more things
  zrep compatible.)

Thanks!
Russell