1. Start the virtual machine 2. Click Devices menu 3. Select Insert Guest Additions CD image 4. Change to the directory where your CD-ROM drive is mounted (typically /media/<user>/VBOXADDITIONS_x.x.x/) 5. Go back to terminal, then key in "sudo sh ./VBoxLinuxAdditions.run" 6. Reboot the virtual machine!
Thanks to the author for that directions in the source provided.
Install dependencies and supporting software and drivers
You need these dependencies. Enter these in terminal: