The phrase "to become legal" means to be made lawful or acceptable according to the rules and regulations of a particular place or system. It refers to the process of something, such as an action or a document, being recognized and accepted as valid by the relevant authorities or governing bodies. For example, when a person applies for citizenship in a new country, they must go through the process of becoming legal by meeting all the requirements and following the necessary procedures. In another context, a business may need to become legal by obtaining the necessary permits and licenses to operate legally within a jurisdiction.