Removing a license key prevents the license server from checking out new connections against that license. To remove a license key:
From the left pane of the StarLicense Manager window, select the server that contains the key you want to remove.
Click the button in the Toolbar or right-click and select the Configuration command, then click the Licenses tab.
From the list of license keys that server is managing, select the license key you want to delete and click on the Remove button.