Image and backup Image question for HA SSO

[daswann]

We just purchased a 5508 HA to pair with an existing 5508 for HA SSO. Without thinking about the backup images I upgraded the new 5508-HA to 8.5.161.0. It has been a while since I did this. Then noticed that the backup images are different; 8.3.140 on the new 5508-HA controller, and 8,5,140.0 on what will be the primary 5508. 

So on the 5508-HA the default active is 8.5.161.0 and the backup is 8.3.140.0. I want both to have 8.5.140.0 as the backup image and 8.5.161.0 as the primary. Can I just boot back to 8.3.140.0 then upgrade to 8.5.140.0 then configure the config boot so that the default active will be 8.5.161.0 with a backup image of 8.5.140.0?  If not what is the best plan of action here. 

Thanks in advance 

[Leo Laohoo]

1. First, the HA will need to be removed so the secondary can boot up all by itself. 
2. Flip and reboot the secondary unit to boot into the secondary image.  
3. Upgrade the firmware.  
4. Reboot the secondary to the new image. 
5. Flip the boot variable statement to boot the newer image. 
6. Enable SSO.