How to add New License keys to Sonarqube 6.7 .4 community Edition?

SonarQube Version: 6.7.4 Community Edition
How to add New lincese keys to sonarqube, please provide step by step details?
Do we need to install any plugins like license manager for this?
Where do we check the exsist list of licenses?
Do we need to restart the server after adding the new license keys?

Please provide the below information. Thank you

Hi,
this was already asked and answered, see
https://community.sonarsource.com/t/how-to-add-licence-key-in-sonarqube/5233/2

//Gilbert

Do we need to restart the sonarqube server after adding the license keys?

Hi,
after entering the license key, you are asked to proceed with the download of the plugins
that come with your edition (developer, enterprise).
Your conf/sonarqube.properties, Update Center section has to be configured correctly.
With the enterprise edition you should have a license for two staging instances.
So you should set up a staging instance, put in the staging license and you’ll see.
Otherwise without a staging instance just try, a restart doesn’t take much time.
Regards,
Gilbert