Straight print, but concentrig bottom layer looks nice (if you ever look at the bottom side)
Insert the G9 socket in the base, with the wires through the hole. Hook them up to your power grid using a spare cable (preferably with a switch).
(All electric work is up to you to sort)
Insert the LED, drill a hole (or print the moon slightly lowered) and fit it over the LED to the base.
Hit the light switch.