Atlassian Licensing
The Atlassian Marketplace allows you to easily purchase or generate an evaluation license for Power Dashboard Reports and Gadgets.
After generating the license key, all you have to do is access the Administration > Add-ons section in your Jira instance and paste the key into the License key field.
Removing an unused license
If you want to remove an Atlassian license that you no longer use, use UPM (for UPM 2.0.1+) or remove the old license key and click Update.