The public broadcaster is embarking on a major digital restructure. As young Australians turn off their TVs and radios, the ABC’s audience is rapidly shrinking. Leigh Sales, one of their most high-profile journalists, said ‘it’s change or death’. But change comes at a cost, and is often accompanied by job losses and criticism. Gabrielle Jackson talks to Guardian Australia’s head of news Mike Ticher and deputy news editor Jo Tovey about whether the ABC can change with the times