They seemed bright enough in my garage with the doors closed and lights off ( no windows ). It was super easy, grounded to the pedal mount bolt, then in the little black covered distribution block/fuse block on the floor behind the ebrake, you pop that cover off, then the right side of it, the 2nd clip has a grey wire in the #8 spot, tapped that for power and they work with the dome lights.
only thing im not sure of yet is these lights are from autozone and the "white" is pretty blue but a small led strip is hard to find these days since vleds ditched theirs, which is what i had in my NBS
Proper writeup with pictures is here
https://www.gmfullsize.com/threads/how-to-install-footwell-lights-nnbs-07.257519/