The document contained is the recommended procedure. Updating will require restarting. You can certainly deviate from that process, if you'd like, but the recommendation I can make is to follow the guidelines in the documentation. I found no alternative option to provide.
Hi Dell Community, Are there any guidelines / procedure of firmware upgrade for stacked switches that provide the least amount of service disruption to stacked switches?   Thanks
Minimal Downtime on Firmware Upgraded of Stacked Dell N2000 Series