To add additional licenses to an existing installation, just create an Activation Key.
•The license type (per user, per PC or concurrent user) from the original delivery is used - See Licence Type
•The Activation Key is generated within the Screen - Administration, TAB Additional Licences
If you are using the Web Activation server, use the Switch: Online Validation required to ensure, that a key can never used twice.
Details for all options see Screen - Administration, TAB Additional Licences