Are we talking about the rear "Spoiler/Wing"? If so, it is indeed held on with screws. I've been unable to find any installation details for 2nd gen models, but it's essentially the same as the 1st gen:
https://www.nissan-techinfo.com/asistgc ... N/1SN8.PDF
9. Screw the spoiler in place using the screws and washers provided in the hardware kit. Tighten All screws by hand. Avoid over-tightening.