I haven't worked with that specific product but certainly plenty of similar products. The short answer is, if you unplug it and reboot the machine it is connected to, you should no longer see the drive in the POST. You may need to remove it from the device manager of your windows server. You may also need to go into your backup application and removed the drive in there as well. Beyond that you should be fine.
If that doesn't work, there really is no harm in leaving the drive in the system simple exclude it from your backup software as a target device.
Chace