Download your purchased graphics library from your Cinemar Registered User's download.
Shut down the MainLobby3 Client application.
Double click on the downloaded file .exe
This will run the installer which will copy the library swf file to the Cinemar\Librarys directory.
Restart MainLobby Client.
The new library will now be available via the Main Menu / Button Edit / library drop down.
As each installed library takes up PC resources when MainLobby client loads, try not to keep unneeded libraries in the Cinemar\Librarys directory. Move unused libraries to a different directory. When needed, just copy the library swf back to the special Librarys directory.