Any "rehab" type program for private loans is at the discretion of the private lender. Some loans/lenders offer borrowers the ability to reduce payments, reduce the interest amount, extend the repayment plan, etc. but its highly dependent on the loan agreement you made with the lender and their own policies. The best way to find out what options might be available is to review your loan documents or call and ask.
As far as refinance, most of the private refinance companies base their decision at least in part on your credit score, so you may find it difficult or impossible with a low score. A cosigner might help.
