[Bootlegronin47]

Have a look at these guides.

http://pharic.blogspot.cz/2013/08/instal...ercap.html
https://ubuntuforums.org/showthread.php?t=1943365

Alternatively, you can use Kali Linux- Ettercap Is preinstalled.

I was contemplating installing Kali but then I'd have to uninstall ubuntu im dual booting windows 7 and ubuntu through Unet idk how to uninstall ubuntu can you show me? Can I use Unet to install Kali?