You can’t very easily turn Twenty Ten into a responsive theme, and highly unlikely that a future upgrade will do so. I would suggest changing to a theme which is responsive from the ground up, like Twenty Fourteen or any of the other responsive themes in the WordPress theme repository.
You can easily switch to a different theme and switch back again (if you don’t like the new theme) without losing anything. As far as “starting over again,” it depends on how much customization you want or currently have. You’ll most likely have to set the menu for the new theme to point to the custom menu that you’ve already created, but that’s a very minor step. Any plugins that you’ve installed for your current site should still work in a new theme.
Try this plugin, for me it worked, it may work for you as well 🙂
http://wordpress.org/plugins/responsive-twentyten/
