Yeah, VHB + overhead = bad idea.
Just take a skillsaw with you, slide it out a few feet, saw it down into whatever size you can handle. Slide a new piece of ACM in its place. You'll have to remove that camera obviously... Alternatively, screw into the trim like johnny said. I'd wager it's polycarbonate, good luck moving a piece of acrylic that long and not breaking it...
But I'm all hung up on why the power is routed like that.