How to say "you don't need to."
Generally 不用. 

e.g.你不用担心。 You don't need to worry/Don't worry.

你不用说。 You don't need to say./Needless to say....



不需要

e.g.你不需要这么早起床。 You don't need to get up so early.

你不需要药。 You don't need medicine. 



不必 (which is kind of odd or archaic)

e.g.你不必再谢他了。You don't need to thank him.



无须 (which is also very formal)

e.g.无须细说。No need to talk about the details.