Debian Live USB Change Brightness on Thinkpad

Thinkpad X201 Tablet.
Debian 8.2.0 Live CD USB Stick.

Steps:
1 su to root

2 set brightness

Debian Live USB Change Brightness on Thinkpad by @sskaje: https://sskaje.me/2016/01/debian-live-usb-change-brightness-thinkpad/