These are al the parts you need.
You have to buy a raspberry pi 3 without 40 pin connector or must cut all pins.

At first add raspberry pi with short bolts 3mm onto the bottom plate.
(don't forget to cut the pins (I did it afterwards)

You have to add the two supports first and place the lcd board, after that you can screw the bottom plate onto it.

Finally plug in the power mini usb and at the top (I screwed it with 2 screws afterwards)

>This is the final result, I'm very happy with it!