How can i de-restrict a 1989 cbr750 hurricane

Perhaps you could give a little more information? Because a 1989 CBR750 Hurricane was far from restricted, with 100+ HP at 10K, it screams!
Now if you are wanting to improve upon that then you would have to identify your goals for one and how much you can spend, not only on parts but on tuning. Many choose to start with a higher flow air cleaner / filter and performance exhaust. Then of course adjusting fuel management. Others choose to increase the displacement of the engine with larger pistons, different cams, and perhaps modified heads. Also set some realistic expectations as this is a 20 year bike with limitations. Hope this helps and good luck.

JP