After the check I started with the dimmer. I drilled a hole for the knob and used two screws to keep it on place.
At the other side of the mill I made a hole for the 230V cable.
The bulb socket fitted perfectly to the brass fitting, so I just had to screw it in...
Then I installed the brass ring with the bulb socket with four brass screws to the top of the coffee mill.
The slide didn't fit anymore, so I used only the front and glued it to the wooden walls.
Finally I closed the lamp body with the bottom.