Notice: It's an extremely dangerous experiment, please don't do it.
A plastic cylindrical box is cut by using a cutter roughly, it will not be good in the first cut, but we can always use a good scissor to make it better.
Then the ERF is attached in the most ugly way, a firm and secure attachment is more than the outlook:-
Another angle to show the tilting angle:-
Finally, to put it at work... you can see light leakage, so it's better to cover it, but since that was a cloudy day, it does not affect much:-
A last note is that, this tilting does not help to remove the secondary shadow.