You make loans like you normally do - private lenders and banks loan anyone the funds they want for higher education.
Except this time the loans are backed by the colleges instead of the U.S. taxpayer. When you put the risk on the schools, you will quickly not only see the cost of education drop (no longer subsidized), but all of the bullshyt Marxists activists masquerading as educators will be quickly be tossed out of the system.
Students will also hold colleges accountable. When you get a degree in something that isn't useful to society, you have no one else to blame but yourself and the college. As the ROI is low and THEY are on the hook (the school is now competing in a free market), they won't offer things there is no future in or have to lower prices. There's no reason a liberal arts major should be paying $100k for a degree and 4 years of time, the same as an Electrical Engineering major.
This will also expose that $100k isn't REALLY about the quality of the education, but the value of the connections elite universities offer. That's one of the prime reasons they cost so much. Americans are not ready for these discussions because they view education as virtue, so any criticism of an institution is viewed as an attack on that virtue and not the worth of the institution itself.