How to repent from sins with (Hadd)?

Some scholars said that if a person commits a sin that has a Hadd (punishment), then there is no problem for him to go to the ruler that establishes the punishments, like an Ameer (ruler) for example; he says that he has committed such-and-such sin and wants to be purified from it. Nevertheless, it is better for him to hide his sin, this is better. Meaning, it is permissible for him to go to the ruler when he commits a sin that has a Hadd (punishment), like Zina (fornication) for example, tell him that he did such-and-such, and request the establishment of the punishment on himself. That's because the Hadd (punishment) is an expiation for the sin. As for the other sins, then conceal them as Allah has concealed them. Likewise Zina (fornication) and so on, conceal them with regards to those other than the ruler. Do not expose yourself. As long as you have repented between yourself and Allah, Allah the Exalted accepts the repentance from his Ibad (worshippers) and pardons misdeeds.