Go into your Favorites bouquet list for your OTA channels, enable "Move" mode, and move them anyway you'd like. Just do this on the Mio itself, using the remote.
You have to save them to a 'Favorites' bouquet FIRST, if you haven't already. Just like with sat channels.
Or, you can do it in the Bouquet editor screen in the WebIF. Either way works fine. I don't even bother with DreamboxEdit and the like anymore. Too many issues making those programs work correctly, unless you are dealing with something like the 2,500+ channels on 105w.