You start building a serious border fence, at least on the southern border, and maybe at least parts of the northern border.
You announce a guest worker program, which can be applied for over the next year or so. The guest worker program provides:
To obtain a card, an applicant would also have to provide proof of identity, and pass criminal background and health screenings.
At the end of the three years, guests could either return to their country of origin, or take an examination on English and U.S. history and culture, to obtain a permanent visa. If they got that, then in another three years, they could take a tougher examination and apply for citizenship.
Meanwhile, the fence is completed, and the border crackdown deters additional illegals. And then you'd have to weed out the illegals that remained in the country, because more than likely, they would have criminal records. And obviously crack down on employers.
What about requiring some form of national identification card with some sort of biometrics? Then outrageous penalties for employers that hire illegals.