How do you upgrade theme without interrupion to visitors?
My CP site has enough traffic, that in any given moment there are likely several people visiting the site.
I want to upgrade to 2.9.3.
Is the best way to use the "maintenance mode" plugin, and say "please check back in ten minutes" or something like that. Then delete the old theme (2.9.2), and freshly install the new theme (2.9.3).
So when transferring via FTP, is it good to delete the old theme and freshly install the new theme.
Or is it better to just transfer the new theme by choosing "overwrite all" without first deleting the old theme?