Is there a legal way to get off sisp supervision early?

Yes, of course. Follow the rules and stay out of trouble. What, did you think there was an easier way?

SISP stands for Super Intensive Supervision Program. It means that you have to report to a parole officer on a regular basis, usually once or twice a week. You are allowed to work or go to school, allowed to look for work, can attend counseling sessions, go to the supermarket or bank for daily living needs, doctor or dentist appointments. But you are basically under strict review at all times. You may even have to have an electronic ankle bracelet.

How you get off SISP is that you basically stay out of trouble, follow the rules laid out, and convince your parole officer that you can be trusted enough that they no longer need to keep you on the SISP monitoring program. You would then be transferred to a less intrusive parole method.

Of course, if you don't like SISP, the other option is violate your parole. Legally you'll be taken off SISP early, as you wanted. Of course, you end up back in prison. So that is probably not the preferred way. :(