I have a backup for Boot Volume. I can create new Boot Volume from it and attach to a new instance.
But I need to save the existing one with all settings. Is it possible to just replace one Boot Volume to another?
There is no direct way to replace the boot volume of an instance. You have to first terminate the instance. So that you can use the boot volume again.
Then you have to create a new instance with same or different settings(as per your need). While creating the instance in the image selection field, there is a tab called boot volumes at which you can select the existing boot volume.