If it's a factory installed option it's most likely the Z51 style spoiler, although it could be the "High Wing" style. Either way, if the car came from the factory with the spoiler installed then it's attached by a series of nuts, bolts and washers and 3M double sided tape. Removal requires that the rear bumper cover / clip be removed in order to access the mechanical fasteners.
If you're sure that it's a factory installation then it's definitely bolted and taped. If there's a chance that it's an aftermarket spoiler then it's possible that it's held on by tape only but it's not likely. Check your window sticker, if you have one, or the factory options list / build sheet under the carpet in the rear cargo area, RH side. Either of these documents would confirm if the spoiler is a factory RPO.
Best of luck
Ross
