Question on changing float bowl gaskets

Hey everyone.

I recently purchased a Honda CB1000 custom. I've had to do a few minor repairs on it. Recently the bike has had trouble staying on after a few minutes of running (starts right up and idles for several minutes before dying as if it's not receiving gas). I checked around and saw that at least one of the float bowls has a dripping leak from the seal and is missing one screw. I'm hoping this is what's causing the problem.

I plan on replacing the gasket and getting a new screw. My question is: is this okay to do while the carbs are still on the bike? I would love to not have to remove the whole thing. It will be a bit tricky to get my hand in to remove the screws but better than the other option. Any related tips much appreciated... thank you.