I have smoked things using the barbecue grill before, and it’s largely the same thing that I did here with an offset smoker.
I will explain the adjustments as needed for each step of the process.
Full disclosure: I decided to start my adventure in smoking a whole fish when the outside temperature was 27°F (-3°C). I certainly don’t recommend doing this, since it was impossible to maintain the temperature I needed to fully cook the fish. I finished the cook of the fish in the oven. But, in fact, what I did constituted a Cold Smoke of the fish: the internal temperature rarely got above 85ºF, but the smoke flavor imparted by the process was spectacular.