On Tuesday, Tiki Barber of the New York Giants said he was ?leaning toward? retiring, and that he had ?pretty much? made up his mind. Asked what would force him to reconsider, he said, ?Nothing.? Barber's business agent, Mark Lepselter, who manages Barber?s off-field career, said it was possible that Barber could change his mind. ?He?s seriously leaning toward it,? Lepselter said of retirement. ?I think he feels he?s perfected his craft, in a way, and is ready for something else.? Ernie Accorsi, the Giants? general manager, said yesterday that he did not want to comment on Barber?s retirement plans until he heard them from Barber. ?You do not replace Tiki Barber, he?s a Hall of Famer,? Accorsi said. ?You have to go beyond the statistics