How to change a guid of a zfs device?

[Mark Murawski]

How would I go about changing a guid of a zfs physical device?  There 
doesn't seem to be any options in zpool or zdb for doing guid changes.

It's a long story, but through a series of drive swaps I've managed to 
really screw stuff up.

Here's my current status

         NAME                      STATE     READ WRITE CKSUM
         zstorage                  UNAVAIL      0     0     0
           mirror-0                ONLINE       0     0     0
             ada4                  ONLINE       0     0     0
             ada3                  ONLINE       0     0     0
           mirror-1                UNAVAIL      0     0     0
             14791054479353866913  UNAVAIL      0     0     0  was 
/dev/ada4s4
             5249816505308091368   UNAVAIL      0     0     0  was /dev/ada1
           mirror-2                ONLINE       0     0     0
             ada5                  ONLINE       0     0     0
             ada10                 ONLINE       0     0     0
           mirror-3                ONLINE       0     0     0
             ada6                  ONLINE       0     0     0
             ada8                  ONLINE       0     0     0
           mirror-4                ONLINE       0     0     0
             ada7                  ONLINE       0     0     0
             ada9                  ONLINE       0     0     0



14791054479353866913  is really /dev/ada1s4 now
5249816505308091368 is really /dev/ada0 now

the problem is, zdb tells me that /dev/ada1 has a guid of 
3184618752700174674
and zdb says /dev/ada0 has a guid of 16592948394566938185

I need to get these to match so that I can reconstruct the pool again