In order to rehab your student loan you have to get in contact with the original creditor or CA and ask them about the program. They usually ask you some income quesitons and set up a payment plan based on your income. They also normally ask for a down payment and then they ask you to make 9 monthly ontime payments. Once you complete the program they will normally delete the collection account, update the original loan as paid as agreed as if it was never in default at all. And at that point assuming you don't have any other negs you will see a HUGE jump. My score went from 650 to 683 when they deleted the collection account and once they updated the original (which showed 120+ days late and collection) to paid as agreed my score jumped to 776. This jump happened within 2 weeks of getting it ouf of rehab!
My loans are through Sallie Mae and I never really defaulted, I just never paid and was finally able to get my payments deferred. I wonder will they be willing to remove the lates for me. Never hurts to ask!!! Congrats on your wonderful accomplishment!!