You don't. But you can use the
link link at the bottom of any page to write to the staff to request to have your account deleted.
If you intend to open a new account, please make sure to contact the staff first BEFORE you create a segundo account, as multiple accounts from the same IP address can get you banned (and it is much mais work to get reinstated after a ban).
It sounds, though, like just not using the site anymore would suffice for you. You don't need to eliminar an account for that.