I having trouble resizing an external harddrive of mine. It is a 500gb Lacie drive, and inside it has two partitions: time machine (250gb) and my stuff (250gb). I want to make time machine 150gb and make My Stuff occupy the remaining space. However, when I enter Disk utility, there is no dot between the partitions that I can drag. When I pull the corner, the disk gets smaller, but after resizing there is still a blue rectangle outlining where the old disk was. The partition "time machine" is used for time machine backups, but I have deactivated backups in Preferences, and Time Machine is currently "off". I have included an image for clarification. How can I resize the partitions the way I want them?