Marquees for games are added or changed in much the same way as any other content to CoinOPS.
Follow the Procedure in the INSTALLATION section of this help file until you have gained FTP access to your xbox console.
Since the introduction of system specific marquee folders in CoinOPS 6, there is a unique directory for each system's associated marquee files. - /coinops/marquees/systemname
(e.g. If I wanted to add a marquee to my Atari2600 game 'Halo' i would transfer my new file to:
Transfer to the relevant directories and restart coinops to see your new marquees.
To Learn more about creating your own Marquees, Contributing and Adding to the ever growing library of supported games within CoinOPS...