It depends on the type of student loans you have. The rehab program that most people are referring to here are for Direct Loans or FFEL loans. Here's the information on the Federal Student Aid Loan Rehab Program http://studentaid.ed.gov/repay-loans/default/get-out.
What type of loans do you have?
As the poster above said, rehab is only available for federal student loans. It also may not be an option for very old loans (I don't think the rehab program has been around forever, maybe someone can correct me?), and it is definitely not an option if you have already rehab'd once in the past.
That's basically your only course of action. If they will accept a reduced amount in return for immediate payment, that's great and you should take advantage of it. Student loans don't go away except in extreme circumstances with a good lawyer, so getting out from under these should be a high priority.