Please don't ping people a few minutes after you've asked a question. These boards are monitored by multiple people and most questions are answered in a timely fashion without needing to message people directly.
You install a basic license the same way you install any other license: https://www.elastic.co/guide/en/x-pack/current/installing-license.html
If you need a new basic license you can get that here: https://register.elastic.co/