TOMB is right. The reflector attaches to a shroud. Behind the shroud there are two bolts going from down to up holding the rail in place. 6mm Allen wrench, iirc. Be careful putting them back in. I watched a guy in AZ get the rack misaligned a tiny bit and instead of figuring out why the bolts weren't threading up easily, he forced them all. It was embarrassing to watch.
There could be a shroud bolt behind the reflector, too. I don't remember that part.