What if someone want to kill his own account on this forum

[HorseRider]

and clear all the data and post he had published.

What should he or she do? thanks.

[DeathAndTaxes]

I don't think there is any automated way to delete all posts but you can use your own post history and edit/delete every single post then request the mods delete your account.

[Maged]

Yup. Go ahead and edit or delete any information you don't want to remain on the forum, then PM theymos when you are ready to have your account deleted.