Broken Windows mirror. How do I restore disk mirror?

Started with Windows and apps successfully running on Disk 0 (1TB Seagate). Bought an exact duplicate HDD, recognized as Disk 1. Followed instructions and used Windows Disk Manager to convert Disk 0 to Dynamic, and configured as a mirror with Disk 1. Everything still worked perfectly. Physically disconnected Disk 0 to test booting from the Disk 1 mirror. Boot failed, and upon reconnecting Disk 0, the PC rebooted (from Disk 0), but mirror was broken.

THEN, my error, instead of properly re-establishing the mirror, I "imported" Disk 1. PC still boots (from Disk 0), but now Disk 1 appears with a drive letter, and Disk Manager does not offer the option to break nor re-establish the mirror. What steps must I take to re-establish the mirror?

Neither Seagate DiscWizard nor the Dell Backup utility seem to work with the dynamic disks. The running application is mission critical, so I hesitate to use "unbranded" utilities.

Thank you in advance for your assistance.

I solved my predicament via the following steps.
***WARNING: The following actions can be dangerous because they erase files (which were not needed in my case). Please do not follow these instructions if you do not understand the purpose of each step.***

1. Remove the Drive: letters assigned to volumes in the broken half disk of the mirrored set. In my case, Disk 0 was fully operational, active and contained the "good" volumes with assigned drive letters C: and E:, and Disk 1 was an old, broken, mirrored copy with now useless volumes assigned drive letters F: and G:.
I removed the drive letter assignments for volumes F: and G:, by invoking the Diskpart utility at the command prompt:

diskpart
> list disk
> select disk 1
> list volume
> remove letter=F
> remove letter=G

2. Delete the old volumes on Disk 1. ***BE VERY CAREFUL to properly identify the useless volumes. This step deletes their contents. *** The volume names in this example will probably NOT apply to you.
> select volume 4
> delete volume
> select volume 3
> delete volume

3. Re-establish a mirror in Disk 1 for each volume in Disk 0.
> select volume 1
> add disk=1
> select volume 2
> add disk=1
> exit

4. Verify that the mirror is operational. Go to Windows Disk Management to confirm that the volumes in Disk 0 are now mirrored in Disk 1. Test that during boot, you can now boot from the mirror ("PLEX").