Take semester off, finish the novel and turn it over to his agent.
What? He didn't have an agent or a publisher? Read his notes. Read what he wrote. If worth the work, complete, turn over to lawyer to arrange an agent and publisher.
If novel stinks to high heaven, just write, "and then a bunch of other crap happened but the world continued unchanged. The end."
If the lawyer won't accept that finished novel to complete the terms of the will, advise him he needs to read the entire work done previously. If it's that bad, he'll quite by the end of the second chapter, say you fulfilled the terms of the will, and the rest of your college studies is a free ride.