Posted: 19/11/2016 at 21:10
That's going to take a lot of hard work! Start by removing the leaves using very sharp secateurs or even a stanley knife - they are tough and fibrous (its common name is New Zealand flax and flax is used to make rope!) I would dig a trench all around it, then start working under it, severing roots with a sharp spade etc. as you go. A mattock would probably be my tool of choice for attacking the roots.