Here are my thoughts on the procedure.
As you should know, ONTAP has a minimum requirement for BIOS and SP firmware images.
You may wish to work with support to figure how far back you can jump.
Referring to
and
The FAS8060 can run BIOS 9.6 from ONTAP 9.0-9.5
The FAS8060 can run BIOS 9.4 from ONTAP 8.2.1 - 9.0
Service-Processor firmware:
the FAS8060 can use SP frimware 3.8 / 3.7P1 from ONTAP 9.3 - 9.5
the FAS8060 can use SP frimware 3.4P2 on ONTAP 9.2 releases
the FAS8060 can use SP frimware 3.3P5 on ONTAP 9.1 releases
To upgrade/downgrade the SP firmware, as far as I know, you need to at least "install" ONTAP and configure the SP.
(give it an IP address)
From there, step backwards a little at a time (unless support gives the green light for major backwards jumps)
I was thinking about procedures, I'd prefer not to post without testing. I do not have any gear to test on either.
High level things:
1. you will need to remove ADP. Doing it in ONTAP 9.2 and higher is easy with the new option 9.
2. You must have whole disks, 7-mode has no concept.
3. The SP firmware should be updated to the version that came with ONTAP. It should auto-downgrade for you
4. You will need to install Appropriate BIOS images They are not auto from what I see.
Hopefully this helps at least a little. It can be done, but be sure, it will be a little painful!
Tim McCarthy, Principal Consultant