Step 1 - Go to the switch user page
From the main screen, press on the user icon in the top left.
Step 2 - Press on the user name
Now press on the username (not the image... just the name) of the user that you want to delete. You will now see a menu pop up with multiple options. Press on "Edit user"
Step 3 - Delete user
Now press on the delete button in the top left of the form.