How to remove lighting from photo booth

Hello! This is my first time creating CC and I'm doing a recolor of the photo booth that came with High School Years. The photo booth has some lighting effects in the shape of the design which I though would be remove with my recolor. I tried following a tutorial on how to remove lighting from objects but it didn't work.

I would really love some help as I'm quite happy with how the objects looks during the day when the lighting hasn't come into effect.