You need an adapter to plug the card into a USB slot on your computer, but once you have it the card shows up on your computer like any other drive that you can explore making it easy to delete/replace one update with a later one. I wouldn't expect Humminbird to release another update for these older models.

Check out youtube for videos on how to operate those units. Doug Vahrenberg's channel is fantastic.

https://www.youtube.com/user/imonbass