Since its a conversion from Hybrid Mode to Native Mode it needs a downtime and it need to be done one by one on both the sups in single chassis.
So the best way will be to arrange some donwtime and take out the standby sup from the chassis and first convert one sup from CATOS to Native IOS and once done take that out and insert the second sup and perform the same steps for conversion.
Have a look at this link which has step by step instructions for conversion from CATOS to Native IOS.
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 custome...