Having spent over a thousand dollars on a lamp, you probably won't blink at the cost of taking it to a lamp shop for rewiring. I don't know how common such shops are. There's one not far from where I live, but maybe it's a really rare hold-out in the market. I would expect the job to cost a hundred dollars or less.
Much of the advice up-thread is probably wrong, by the way -- though there's no way to know for sure without more detailed specs than were available at the linked site.