Hi there,
Unfortunately, this is still kind of difficult to do in the site editor! However, there are a few ways of doing it.
Firstly, you can add the Ollie Dash plugin, which comes with a setup wizard where the Site Icon is a setting. You can download Ollie Dash here (it will be available via wp.org soon!). Once you install and activate the plugin, go to Appearance → Ollie → Theme Setup → Your Brand. There is a setting for Site Icon in there. Here’s a complete video on the Ollie Dash plugin.
Alternatively, you can still access the WP customizer by going to the link directly. You’ll can find it by using a link like this:
yoursite.com/wp-admin/customize.php
In the customizer, there is a setting for site icon.
Hope that helps!
