Install Default App Manager to make changing the default easier. (It still takes you to the same place, but it takes you to the right place for any particular app, to either make it the default or to remove the default from the current default app (which you'll have to do first for the Launcher app.) Although if you open Nova Settings and scroll down, you should see Select Default Home in the Nova section (counting Advanced and FAQ, that should be about the 6th item up from the bottom).
Hi you could change the launcher by downloading xos launcher then go to set as default then you could use xos or use any launcher available as of now this is the only way to change the launcher in cherry os