...
After generating the license key, all you have to do is access the Administration-> Plugins section in your JIRA instance and paste the key into the corresponding plugin textbox.
Kepler Licensing
The Kepler license is a binary file (usergrouppicker-pro.lic) which must be placed in the <JIRA_HOME>/kepler folder. You may obtain this file contacting cPrime support team
You can view details for your Kepler license all the license files situated in the kepler folder, by accessing the the Kepler Licenses page from Kepler General Parameters -> Licensing menu: page from Administration > Add-ons > Licensing menu.
The page shows the expiration and maintenance date, user limit and validity message for each selected kepler license.
...