Translation English - Spanish (Castellano) TODAY

Looking to get our website translated into Spanish (Castellano, from SPAIN). It is one single language file, containing all the strings the website uses. The structure is always as follows: $lang["Contact us"] = "Contact us"; Here we only need to translate the part after the = like this: $lang["Contact us"] = "Contactanos"; We need the translation to be done on the informal "Tu" version not "Usted". I am attaching the file for your review. Delivery needs to be done today.