Becker Head Unit Becker Head Unit Release Keys Help Needed?

Becker Head Unit Release Keys Help Needed? - becker head unit

I have a Renault Laguna II, a division of Becker / Carminat head. I bought communicate the key to remove the display unit, but can not make them work. What is the right way? To what extent the sequence of buttons on the front? Do I have to move, if it in itself? (Things) - All suggestions greatly appreciated.

These are the keys: http://94.76.216.14/CarminatTool_TTL.jpg
This is the main unit: http://94.76.216.14/carminat_TTL.jpg