The bottle holder just sits on any shelf as it just allows you to rest bottles on it
The strip with the 10 teeth goes onto the milk tray edge on the door. It will lip onto the front of the milk shelf and the teeth go on the inside of it as the teeth just help hold the bottles in there.
And the egg trays just sit inside the other shelfs on the door and its up to your which one you use.
Hope this helps you. If you need anymore info just get back to me.