However I wouldn't prefer that way unless I have tested everything in advance before.
What I shall recommend, is that to connect a PC with hyperterminal and then use Remote Control that PC using any Internet based tools e.g. even MSN Messenger would allow that and do the stuff, coz if there is only one router to the site and if that becomes inaccessible then its all gone case.
Moreover to make the things easier, I shall recommend that you ensure that there is enough space in the flash for both the IOS or else the later would delete the former and you need to re-install the IOS.
Secondly if there is enough space you can specfiy which IOS to load by specifying through the commands.
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...