Topo maps, can't delete them.

It seems that the north American version has 18gb of maps preloaded and that means I can't add marine charts so I'm a little upset. Apparently I have no way to actually delete 2 of the maps I don't need.  This is what Express is showing me but there's no way to delete a map.

Am I left with going into the \Garmin folder on the watch and hoping I delete the right ones?  Really?of

    1. Select Manage Maps to add or remove maps from your device.

    2. Check or uncheck maps to add or remove them from your device.

    3. Select Apply Changes.

  • I fit the whole G2 charts on my new 8, if anyone was wondering. I selected and removed any available options they gave me in express, that's it. I have the southeast 24K topo, and street navigator on it as well. All of that fits, but there's no room for additional data on any app. If I can figure out how to remove the paid for download maps, I don't mind switching the files depending on what I'm doing. It's rare I would need Topo of Colorado and Marine charts in South Florida at the same time. This will give the watch enough room to operate and save data along the way, including music and phone interactions. I just can't figure out how to remove the paid for maps!