I see the drives are recognized and mounted, so that's a good start. They are being mounted as read-only though. Perhaps your Windows session wasn't closed properly, or things were still in suspend or hibernation mode. Or possibly one or more disk errors are present on your HDDs. I would double-check the disks on a Windows machine first.
After that, in Kodi, use the browse function in Videos, or Kodi's File Manager itself, and locate the drives via the /var/media path.
Thanks