The file comes in 3 parts. Simply print out all of the files. I found that no shells and 60% infill was good for the top, 1 shell and 25% infill worked for the bottom, and no shells, 40% infil was good for the base. all three prints in succession will be about 5 and a half hours. Once printed find a nail that fits the holes in the base and bottom of the island depending on however large you've scaled the print (diameter is all that matters really, native size is a little bigger than 3mm) and place it in the bottom of the stand. To adhere the top of the island onto the underside, I recommend brushing acetone onto both surfaces, lining them up, and then holding them together for a few minutes. The acetone essentially welds the to parts together. After that, just place on the nail, and enjoy! one might consider painting it or flocking some grass onto the top, or adding scale trees. Native print size is about 1:720 scale.

Alternately, if you prefer lighthouses sans floating islands, then you can print only the top part and do what you will with it.