The easiest way to do this is use a compact flash card with the rommon file already copied to it. If you don't have one you can just copy the rommon upgrade utility to bootflash.
Since you are running SSO there "should" be little to no downtime for the users connected to the switch. I would recommend performing the upgrade after hours just in case there are any unplanned issues.
I would first fail over the active supervisor by consoling into and type
"redundancy force-switchover" which will reboot the active and let the standby take over for the switch. You will want to break the boot sequence in rommon and boot the rommon upgrade utility (from CF or bootflash) instead of the IOS. For example:
We are pleased to announce availability of Beta software for 16.6.3.
16.6.3 will be the second rebuild on the 16.6 release train targeted
towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are
looking for early feedback from customers befor...
Introduction Featured Speakers Luis Espejel is the Telecommunications
Manager of IENova, an Oil & Gas company. Currently he works with Cisco
IOS® and Cisco IOS XE platforms, and NX to some extent. He has also
worked as a Senior Engineer with the Routing P...
In this session you can learn more about Layer 3 multicast and the best
practices to identify possible threats and take security measures. It
provides an overview of basic multicast, the best security practices for
use of this technology, and recommendati...