I did not install these myself, but my BIL didn’t seem to have any problems replacing existing lights. (The wall surface was flat wood siding). I love how these look. They provide a bright filtered light in all directions. The bulb shade is plastic, the outside has three glass panels that leave a half inch gap open on each side. Hard to explain. The standard glass can be replaced, just get a piece cut to size. The dusk to dawn option works fine, but since they are on the darker north side of the house they stayed on too long. So, I replaced the standard wall switch with a digital one to control them, rather than using smart bulbs.