Two barrel carb? On a lot of carbs that feature a shutoff solenoid, you have to remove (unthread) the solenoid to take off the bowl. In some cases, the solenoid is the only thing holding the bowl in place. On yours though, it looks like there may be a couple of screws also holding the bowl in place.

Remove the fuel filter and let the fuel run from the line into a pan so you know the water is out. The water will be "foggy" due to the alcohol you put in the tank. It is best to run that all out tomorrow if you can. If you feel you need to do carb service,your best bet is to remove the bowl with the 2 screws as Mownie described. The solenoid doesn't thread into the carb body directly. Also, the bowls on these like to rust. Be cautious about the seal at the bottom the fuel pipe. You will need to drop the throttle control down- just a bolt on each side. With the bowl off, you can take a piece of clean fuel line and gently blow through the line in through the pump --> carb by mouth or super low air pressure so the pump isn't damaged.

*****"Also, the bowls on these like to rust".*******DING, DING, DING. If that is true, some rust particles may have broken loose and partially blocked a pilot jet. With a blocked pilot jet, it might be neccessary to apply choke to reduce the amount of air entering the carb (blocked pilot reduces fuel, mixture is too lean to run, choke reduces air....richens the mix) Because this two barrel carburetor assembly is essentially 2 "one barrel carbs" in a single body, each cylinder is fed from its own, dedicated barrel. This would allow one cylinder to have a clogged pilot and run weaker (and hotter) than the opposite cylinder being fed the right mixture by its "unobstructed" barrel. Because a pilot jet only feeds a small amount of fuel into the induction stream (main jet feeds the majority) for starting and low RPM running, you might not even notice the reduction of power in most conditions. But the lean burning cylinder sure will notice. You might want to pull the spark plugs and "read them". White or light gray color indicates lean and hot, light brown or tan is normal. Of course black would indicate overly rich, but since you are now needing to apply choke to get the engine started.....it's a bet that you don't have a too rich mix.