Certified GKH Gardening Expert
This is going to be a long, difficult process. They will spread by tubers so removing the parent plant will not be enough.
I would recommend digging the plant out, and tilling or breaking up the area as much as possible to try and kill off the living portions of the roots and tubers. Next, you will want to pour boiling water on the area once or twice a day for two or three days.
With some vigilance, you can get rid of them. This article will offer more information on eradicating this persistent plant: https://www.gardeningknowhow.com/ornamental/foliage/yucca/removing-yucca.htm