not easily!!! I've read that crushing the stems and treating it with a systemic weedkiller helps, but it may take a while.
Try using Tumbleweed, SBK Brushwood Killer or another of the glyphosate weed killers. They are all absorbed into the plant via the leaves, but take care near plants you want to keep, cos they're not selective treatments!!!
You can't...
The rhizomes go down at least a metre, and poison will not reach that far. It's been here for a hundred million years or more, and a bit of herbicide is no challenge for it.
The only thing I've found is really persistent weeding (ideally including digging over), which will eventually reduce it to a tolerable level.