Suburban rear spoiler

[JGKIII]

I removed the rear spoiler on my 16 Suburban. I want to add some ICC lights to the top and several led warning lights to the rear edge adjacent to the 3rd brake light. I was unable to separate the two pieces. The upper painted piece and the lower black piece. I tried prying and pulling until I was afraid of breaking it. Is it held together by friction clips or what? Any information will be appreciated.