A long-time subprime mortgage player, Option One, believes that business as usual won’t work in the new subprime market. So, the H&R Block subsidiary is making major changes to its process and operations, with an eye toward paring costs and creating more efficiency. “We are convinced that the operating models that we have used successfully for 10 years are not going to work in the future,” said Steve Nadon, president of H&R Block’s Consumer…