Don't pay maintenance fees
In DRI you can relinquish your points by not paying the maintenace fees. If your points are paid in full, DRI will take them away from you. You will get a certified letter in the mail and they will warn you about not paying the fees and your points will be gone of their records.
However, they must be paid for. You cannot have a loan on them. Look in the legal document on the DRI website and it tells you about not paying maintenance fees on your points.