All the meshes are hierarchically parented, so its necessary to grab, rotate or scale the right object to operate the entire model. The main object in the parent tree is melbourne_main. All the texture files needed are packed into the blender file. All the models have real-world scale. The cloches (shades) of the lamps can have two different materials for the matte glass part - matte_glass_principled BSDF and matte_glass_v2.0. The second one gives a little more realistic result, transmits more light and produces less noise in cycles renderer. It is highly recommended to use high amount of samples. Both matte glass materials aren't intended to use with eevee render engine.
You can rotate every cloche hinge around its local Z-axis, and every cloche around its local Y-axis to adjust the lamp. Those objects origins are placed so, you dont have to worry about rotation pivot point.