Put the main part to the pad so that the cup holes are at the printing bed and the big opening is at the top.
Print the brick-light-cup 4 times
The rest should be obvious.
I did my print with 0.4 mm print head and 0.15 mm layer height
Mounting to the ceiling:
First screw the pad and the bulb holder platform to the ceiling (You may need to increase the height of the pad if you have a rough ceiling) - don't forget to drive the wires with the bulb holder through the hole in the pad and platform
Insert the bulb-holder in the holder of the platform and insert the bulb
Insert the cups to the main part (you can glue them if you want - I didn't need to)
Put the main part on the ceiling turned a bit to the side and then turn it back so that the flaps slide in between the ceiling and the bulb platform (to the slot created by the pad)
Warning: Use only LED bulb! Heat from normal light bulb could melt the plastic