            install a new, fresh copy of <span class="code">weewx.conf</span>,
                which you will then have to edit by hand. Thereafter, V2.X upgrades
                should be automatic.
            </li>
            <li>Custom services. If you have written a custom service, it will have
                to be updated to use the new engine. The overall architecture is
                very similar, except that functions must be <em>bound</em> to
                events, rather than get called impl