1. Download the Gliffy JIRA Plugin JAR/OBR file from the Atlassian Marketplace listing: https://marketplace.atlassian.com/plugins/com.gliffy.integration.jira/versions
2. Open the Administration menu and select Add-ons.

3. Log in with your JIRA Admin credentials.
4. In the sidebar, select Manage Add-ons.
5. Select Upload Add-on.

6. Click on Choose File and browse your computer for the Gliffy JIRA Plugin file you downloaded in step 1 and click Upload.

7. The plugin will be uploaded to JIRA and will be automatically installed. Check the Manage Add-ons screen to ensure that the plugin is available and to manage your license.