Do you remember that song, "Do the bump".

You should ask for assistance by a pro, but I lived with a conservationist for a few years and we had to tackle our garden. The most important things is that you DO NOT put it to compost.

It needs to be pulled out with the roots intact. Then hung to dry ( preferably on concrete or similar or even from the branch of a tree), because if the roots are left touching soil, it will continue to grow. You then need to burn it, to make sure it is destroyed.

The best time to do it, is now, before the flowers seed, but when you can clearly see where it is. Don`t do it when it is seeding, as the seeds go everywhere and you will end up with an even bigger problem. You may have to do a couple of years of this before it completely stops coming through.

Hope that helps!