Well, if the card you have is full; then you would need to remove maps you don't need to make room for what you do want. It is like making space on your Hard drive for your PC to load Microsoft Word. If your card is small, you can always move up to a bigger one (256GB max). Current shipping Furuno USA units come with a 256GB card pre-loaded with data. (licence charts still require unlock). If you really don't like doing your own downloads, you can buy the pre-loaded card with current data from your Furuno USA dealer. (TZT-CHT-SD3) If you are outside the western hemisphere then you should speak to your local distributor for options. If you currently have licence charts, your unlock code will only unlock the version you purchased and older. So if you update your maps you will need to consider upgrading your chart licence or copy the older versions you have licence to over to the new card. Dealers can normally provide on boat services and downloading also, so you might talk to your dealer to see what they would charge you for services if you prefer not do it yourself. The charts priced $0 are free.