“This part explained how people could be chosen or not chosen to be on a jury for a trial, but it's not used anymore.”
This section of the law, which was about challenges and directions to stand by during a trial, no longer applies. It was removed from the Crimes Act 1961 on 1 May 1982. If you want to know more about how juries work now, you would need to look at the Juries Act 1981.