I agree with Cocoa_girl. He said he would show. Nothing about being nice. nor prepared. I would go to gringotts have them put a stop on any bill sent to them from Hogwarts not to pay. Show up with no trunk, no books, no wand. Also send off a letter to the minister, the Head of the DMLE and a reporter from the Prophet (he had to have read that in a book) to attend the opening cerimony. I assume that by putting the sorting hat on its a magical binding contract to attend. So he shows up in jeans and shirt not uniform and refuses to put it on. There in front of the entire school the press and the wizarding world tell him how he loathes the headmaster who took away 5 years of his education and his right to chose. He produces the letter of decline from the Deputy headmistress and then asks her to confirm that he declined to attend. What an up roar that would cause! But hey we already know that he's smart and now full of hate. What things he can get up to.