I have run on my own for several years, without any guidance or structure, anywhere from easy 30 to 90 mile weeks. I finally got serious and started running 90+ mile weeks and ran under 2:25 last year in a marathon, but want to get an OT qualifier. I am looking at San Diego or Grandma's in June for sub 2:19. I have run 100 mile weeks (just easy base mileage) since December, what should I specifically start doing to get ready?